Mastigoproctus Pocock, 1894: 129, 130; Kraepelin, 1897: 36; Kraepelin, 1899: 223; Pocock, 1902a: 46; Shipley, 1909: 312; Hirst, 1912: 237; Hartline, 1923: 148, 149; Mello-Leitão, 1931: 25; Werner, 1935: 468; Takashima, 1947: 42; Snodgrass, 1948; 12, 27; Roewer, 1954: 57; Besch, 1969: 728; Weygoldt, 1972a: 23, 24, 29, 44, 45, 48; Rowland and Cooke, 1973: 68; Phillips, 1976: 397, 401, 403; Weygoldt, 1978: 145, 146, 154, 155; Valerio, 1981: 15; Mann, 1984: 149, 150; Legendre, 1985: 44; Haupt et. al., 1988: 883; Weygoldt, 1988: 189, 190, 194; Ruppert and Barnes, 1994: 334; Barriel and Tassy, 1998: 199, fig. 3; Dunlop, 1998: 291, 293, 294; Proctor, 1998: 160; Armas and Maes, 1999: 14; Shultz, 1999: 92, 96, 104, 105, 109, 111; Armas, 2000: 2; Ax, 2000: 103, 390; Adis et al., 2002: 8; Armas, 2002: 42; Dunlop and Martill, 2002: 329; Harvey, 2002: 363; Rowland, 2002: 194, 195; Giribet, 2003: 558, fig. 1; Harvey, 2003: 65; Armas, 2004: 23, 24; Regier et al., 2005: 396, fig. 1; Víquez and Armas, 2005: 95, 96, 98; 2006: 37; Ballesteros and Francke, 2006: 156; Punzo, 2006: 266; Víquez and Armas, 2007: 39–42; Armas and Víquez, 2007: 508; Dunlop et al., 2007: 124, 125; Huff et al., 2008: 1, 2; Dunlop and Tetlie, 2008: 551; Giupponi and De Vasconcelos, 2008: 18; Tetlie and Dunlop, 2008: 299; Teruel and Armas: 2008: 32; Armas et al., 2009: 4; Beccaloni, 2009: 113, 115–117, 124; Haupt, 2009: 15, 18; Villareal and Giupponi, 2009: 145, 146; Lukhtanov and Kuznetsova, 2010: 1117, fig. 2; Teruel, 2010: 193; McMonigle, 2013: 7, 10, 12, 16, 26, 28, 30, 31, 49–52, 55–57, 59, 65, 68, 77, 80–82, 85, 88, 89, 91, 94, 98, 99, 102, 106, 107, 112, figs, unnumbered, 4–6, 8, 9, 14, 27–29, 33, 34, 36, 37, 47, 49, 53, 54, 58, 60, 61, 66, 68, 79, 82–84, 86, 90, 91, 94, 97; Weygoldt and Huber, 2013: 348: Maquart et al., 2016: 79; Monjaraz-Ruedas et al., 2016: 120; Selden et al., 2016: 7; Chenyang and Huang, 2017: 101, 104.

Diagnosis: Mastigoproctus differs from Mayacentrum Víquez and Armas, 2006, Ravilops Víquez and Armas, 2005, and Thelyphonellus Pocock, 1894, in the presence of a well-developed carina that extends from the lateral ocelli approximately two-thirds the length of the carapace toward the median ocular tubercle. Mastigoproctus differs further from Thelyphonellus in the presence of a pair of pygidial ommatoids, which are absent in the latter genera, and from Ravilops by the shape and macrosculpture of the pedipalps, which are elongate, punctate, and tuberculate in Mastigoproctus, but short and smooth in Ravilops. Additionally, Mastigoproctus differs from Mayacentrum in the structure of the tergites and sternites. Only the anterior tergites (I–III) are divided medially in Mastigoproctus, whereas all tergites are partially or completely divided in Mayacentrum, and sternites II and III are unmodified or with at most vague lateral swellings in the adult male of Mastigoproctus, whereas sternites II and III are distinctly bilobed in the adult male of Mayacentrum.

Mastigoproctus differs from Mimoscorpius Pocock, 1894, as follows. The pedipalp femur of the adult male bears a pair of teeth, one on the retroventral surface and one on the proventral surface, in Mastigoproctus whereas only one tooth is present on the proventral surface in Mimoscorpius. The pedipalp tibia of the adult male is distinctly longer than wide in Mastigoproctus but almost as wide as long in Mimoscorpius. The tibiae of legs II–IV each possess a single ventrodistal spur in Mastigoproctus whereas two ventrodistal spurs are present in Mimoscorpius. The seminal receptacles are short, triangular, and posteriorly directed in Mastigoproctus but tubular and kidney shaped in Mimoscorpius.

Mastigoproctus differs from Valeriophonus Víquez and Armas, 2005, as follows. The tibiae of legs II-IV each possess a single ventrodistal spur in Mastigoproctus whereas a ventrodistal spur is present only on the tibia of leg IV in Valeriophonus. The pedipalp of Mastigoproctus is elongate and without a lobe on the retrolateral surface of the fixed finger, whereas the pedipalp of Valeriophonus is short and robust, with a pronounced lobe on the retrolateral surface of the fixed finger. The macrosetae comprising the stridulatory surface of the pedipalp coxa are randomly scattered in Mastigoproctus but evenly aligned in Valeriophonus.

Thelyphonus giganteus Lucas, 1835: unpaginated, pl. 8; Lamarck, 1838: 117; C.L. Koch, 1843: 21, 22, figs. 767, 768; Gervais, 1844: 12; C.L. Koch, 1850: 85; Wood, 1863: 374; Butler, 1872: 201; Marx, 1888: 42; 1892: 252–254; 1893: 54, 55.

Thelyphonus excubitor Girard, 1854: 236–238, pl. XVII, figs. 1–4 (synonymized by Wood, 1863: 374).

Thelyphonus rufus Butler, 1872: 205, 206, fig. 8 (synonymized by Pocock, 1894: 130).

Thelyphonus (?) rufus: Tarnani, 1890: 538.

Thelyphonus (?) giganteus: Tarnani, 1890: 538.

Mastigoproctus giganteus: Pocock, 1894: 130; Kraepelin, 1897: 37, 38, figs. 10b, 38b; Lönnberg, 1897: 190; Banks, 1898: 289; Kraepelin, 1899: 224 (part); Banks, 1900: 422 (part); Kraepelin, 1901: 263; Pocock, 1902a: 47, pl. X, figs. 1–4; 1902b: 170, figs. 40a, 41a, b; 1902c: figs. 2, 9; Werner, 1902: 606; Borner, 1904: 5, text figs. 9a, b, 19, 60, figs. 4, 6, 49, 50, 56–58, 61, 97; Tarnani, 1905: xi; Comstock, 1913: 19, fig. 14 (part); Petrunkevitch, 1913: pp, fig. 17; Patten, 1917: 251–275, figs. 1, 3, 4; Bradley, 1919: 435, 437, fig. 2; Barrows, 1925: 500, figs. 34, 35; Franganillo, 1930: 92 (misidentification); 1931: 48 (misidentification); Mello-Leitão, 1931: 27, fig. 11; Kästner, 1932: figs. 19, 37, 65; Werner, 1935: 468, figs. 21a, 27, 37, 42, 43, 52, 66, 75, 80, 97; Snodgrass, 1948: 11, 27–31, figs. 4a, 5b, 9a–h; Gertsch, 1949: 17; Millot, 1949a: fig. 49; 1949b: figs. 287, 290, 292a, b, 294a, b, 297a, b, 298, 299; Petrunkevitch, 1949: figs. 1, 2, 31, 33, 43–46, 49–52 (part); 1952: 5, fig. 1 (part); Henry, 1954: 2, 3, figs. 1, 2; Petrunkevitch, 1955: figs. 33(2), 84(2); Janetschek, 1957: figs. 5, 6; Eisner et al., 1961: 272–297, figs. 1–22 (part); Savory, 1964: 166 (part); Waterhouse, and Gilby. 1964: 986; Roth and Eisner, 1962: 112, 115, 120; Kästner, 1965: fig. 514; Barr and Reddell, 1967: 259; Cloudsley-Thompson, 1968: 146–148; Kästner, 1968: 117, 119, figs. 10(1); Legendre, 1968: 36, fig. 27; Levi et al., 1968: 116, fig.; Peters, 1968: 337, fig. 1C; Besch, 1969: 730, fig. 6; Horne, 1969: 155–159; Weygoldt, 1969: 353, 356, fig. 8; Reddell, 1971: 28; Crawford, 1972: 531; Weygoldt, 1972a: 23, 29, 34, 45, figs. 3a–c, 6b, 7a–d, 13b; 1972b: figs. 5a–e, 6; Firstman, 1973: 5, 22, 23, figs. 14, 15; Rowland and Cooke, 1973: 68; Cutler and Richards, 1974: 1394; Weygoldt, 1975a: 311; 1975b: figs. 2a–e, 5a–c; Phillips, 1976: 397, 398, fig. 1; Ase, 1978: 238, 241, figs. 21–23; Yogi and Haupt, 1977: 53, 55; Cloudsley-Thompson, 1978: 186, 188; García Acosta, 1980: 43; Haupt et al., 1980: 205–213, figs. 1–8; Levi, 1982: 74, pl. 94; Courtens et al., 1983: 238; Homann, 1985: 70; Itokawa et al., 1985: 65, 66; Ahmed et al., 1986: 296, 301; Haupt et. al., 1988: 883; Shultz, 1989: 11, figs, 1d, 5d, 9d, 15d; Coddington et al., 1990: 11; Crawford, 1990: 432–434, fig. 16.5; Meinwald, 1990: 27; Weygoldt, 1990: 84, 85, figs. 2C, 2E; Selden et al., 1991: 245, fig. 5; Shultz, 1992a: 148–150, figs. 1, 2; 1993: 335–365, figs. 1, 2a–c, 3a, b, 4a–d, 5a, b, 6, 7a, b, 8, 9a, b; Wheeler et al., 1993: 20; Dunlop, 1994: 267; Caycho, 1994: 171; Ruppert and Barnes, 1994: 633, 634, figs. 13–13; Meinwald and Eisner, 1995: 14, fig. 1C; Vázquez-Rojas, 1995: 35, 36; Wheeler, 1995: 324, table 1, figs. 2, 8a, 8b, 8c, 9; Vázquez-Rojas, 1996: 67–69; Wheeler, 1996: 5; Regier and Shultz, 1997: 905; Wheeler, 1997: 89; Farris and Källersjö, 1998: 165; Seiden and Dunlop, 1998: 293, 294; Wheeler and Hayashi, 1998: 179; Shultz, 1999: 82, 88: Punzo, 2000: 385–387; Alberti, 2000: 213, fig. 5a; Ax, 2000: 104, figs. 47b-g; Klompen, 2000: 808; Shultz, 2000: 403, 404; Coddington and Colwell, 2001: 211; Giribet et al., 2001: 158; Dunlop and Martill, 2002: 329, 332, figs. 5a, b; Giribet et al., 2002: 14; Weis and Melzer, 2012: 364, 365; Weygoldt, 2002: 466–468, fig. 634; Harvey, 2003: 66; Attygalle et al., 2004: 581; Haupt, 2004: 159, figs. 3a-d; Haupt and Müller, 2004: 579, 580; Giribet et al., 2005: 323; Punzo and Olsen, 2005: 206– 211; Ballesteros and Francke, 2006: 156–161; Hassanin, 2006: 101, 103, 113; Punzo, 2006: 266–268; Dunlop et al., 2007: 125; Jones et al., 2007: 586, 588; Klompen et al., 2007: 940; Bourlat et al., 2008: 25; Huff et al., 2008: 1–9; Masta and Boore, 2008: 950, 953; Regier et al., 2008: 923; Schönhofer and Martens, 2008: 526; Beccaloni, 2009: 111, 117, 120, 122, 123, 125, 126, figs, unnumbered 112, 118; Carrel and Britt, 2009: 500–502, figs. 1–4; Haupt, 2009: 14–16, figs. 1, 4, 10; Kern and Mitchell, 2011: 2, 4, figs. 1–5 (part); Klimov and OConnor, 2009: 604, 605; Giribet et al., 2010: 413; Ferreira et al., 2011: 8, 10; Heethoff et al., 2011: 1041; Rehm et al., 2012: 3, 5, 11, fig. 1; Van den Borne et al., 2012: 447; Armas, 2013: 91–94; Hembree, 2013: 141–162 (part); Kropf, 2013: 43–56; Lamsdell, 2013: 1–27; Marchioro et al., 2013: 580–603; McMonigle, 2013: figs, unnumbered 69–76, 101 (part); Schmerge et al., 2013: 116–128; Borner et al., 2014: 79–87; Raguraman and Kannan, 2014: 173–205; Redmond, 2014: 120; Sharma and Giribet, 2014: 255; Sharma and Wheeler, 2014: 57; Sharma et al., 2014: 2964, 2966, 2980, fig. 1I; Teruel and Rodriguez-Cabrera, 2014: 115– 117; Ferreira, 2015: 3; Hils and Hembree, 2015: 1–62, fig. 4(3); Karasawa et al., 2015: 352–363; Nguyen and Hermansen, 2015: 81–94 (misidentification); Shear, 2015: 78–117; Wolff and Strausfeld, 2015: 38–44, fig. 2(1); Yamasaki et al., 2015: 18; Barrales-Alcalá et al., 2016: 26, 46, figs. 1A-D; Cabezas-Cruz et al., 2016: 303–319; Pinto dos Santos et al., 2016: 1179–1193; Fernandez et al., 2016: 874, 877, fig. 2; Gomes and Palma, 2016: 3–19; Hembree, 2016: 262–297, figs. 2B, 4D, 7A-E; Klußmann-Fricke and Wirkner, 2016: 1084–1103; Lerma et al., 2016: 293–298; Miether and Dunlop, 2016: 103–119, fig. 5K; Monjaraz-Ruedas et al., 2016: 118–134, fig. 6A, B (part); Starrett et al., 2016; Watari and Komine, 2016: 49–54; Clouse et al., 2017: 2, 5–7, fig. 1d; Cruz-García et al., 2017: 705, 706; Gallant and Hochberg, 2017: 7, 8, 11, figs. 2, 3, 6; Nurhayati et al., 2017: 33, 35, 38; Sabroux et al., 2017: 5, 29; Grams et al., in press: 5, 8, 20, 33, figs. 1, 5, 9.

Type Material; Thelyphonus giganteus: holotype ♀, Mexico (Museum National d'Histoire Naturelle, Paris) [not examined]. Thelyphonus excubitor, holotype ♀, Red River, “Louisiana” (Museum National d'Histoire Naturelle, Paris?) [not examined]. Thelyphonus rufus: holotype ♀ (Natural History Museum, London?) [not examined].

Diagnosis; Mastigoproctus giganteus resembles M. floridanus and M. tohono, sp. nov., from which it differs as follows. The carapace epistoma is visible in dorsal aspect in M. giganteus but not in M. tohono. Spines S1-S5 on the prodorsal margin of the pedipalp trochanter of the adult male are all sharply pointed in M. giganteus whereas spines S4 and S5 are blunt in M. floridanus and M. tohono. The punctures on the retrolateral surface of the pedipalp femur are markedly cristulate, providing a rugose texture in M. giganteus, whereas the punctures are weakly cristulate in M. tohono, and not cristulate in M. floridanus.

Description; The following description is based on five males and four females.

Total length: Maximum length from anterior margin of carapace to posterior margin of opisthosomal segment XII (pygidium) in adult specimens 60.1 mm (♂) and 62.4 mm (♀) (table 1).

Color. Carapace dark reddish brown, anterior and lateral margins dark brown. Tergites I-IX dark reddish brown, posterior and lateral margins darker. Sternite I dark reddish brown; II and III light brown; IV-IX and pygidium dark reddish brown. Flagellum brown, segments with reddishbrown macrosetae. Pedipalp trochanter, femur, patella, and tibia dark reddish brown, mesal surfaces with reddish macrosetae; patellar apophysis, fixed finger, and basitarsus blackish, with few reddish macrosetae. Legs I-IV reddish brown; II-IV coxae, ventral surfaces reddish brown.

Carapace: Epistoma visible in dorsal aspect. Pair of strongly developed carinae anterolaterally, extending from lateral ocelli to two-thirds the distance to median ocular tubercle (fig. 10A, E). Three pairs of lateral ocelli; anterior ocelli larger than median and posterior ocelli; anterior two pairs slightly separated from posterior pair by tubercle, distance between median and posterior ocelli three times distance between anterior and median ocelli. Median ocular tubercle smooth, situated in anterior 10% of carapace (table 1); distance between ocelli almost 1.5× ocular diameter. Carapace surfaces granular, with sclerotized crests mediolaterally. Posterior fovea present, distinct.

Chelicerae: Retrolateral surface with stridulatory surface (plectrum), comprising approximately 20 long, stout (ca. 13 times longer than wide), anteroventrally directed spiniform macrosetae (figs. 4A, B, 5A, B); mesal surface with few short, stout, anteroventrally directed spiniform macrosetae.

Pedipalps: Cuticle punctate with cristulae on retrolateral surface. Coxa, retrolateral surface punctate; ventral surface smooth; coxal apophysis with one terminal spine; prodorsal surface with long, retroventrally directed macrosetae inserted in cristulae, forming stridulatory surface (pars stridens) (fig. 6A, B). Trochanter longer than wide (♂), or subequal (♀); retrodorsal surface punctate and setose; prodorsal margin with five sharply pointed terminal spines (S1-S5) and one subterminal accessory spine (AS), varying in size such that S3 ≥ S4 > S5 > S2 > SI > AS (♂; fig. 7A) or S4 > S5 > S3 ≥ S2 > S1 > AS (♀; fig. 7B); space between S3 and S4 equal to or greater than length of S3 (♂) or equal to space between S4 and S5 (♀); prolateral surface with several spiniform tubercles and reddish setae (♂); proventral margin with two spines (♂). Femur laterally compressed (♂) or terete (♀), variable in length, two (♀) to three (♂) times longer than wide (table 1); prolateral surface with two spines, one prodorsal, short, sharply pointed, the other proventral, tubular, with sharp projection terminally, length one-quarter to one-sixth femur width (♂ ; fig. 9A) or short, sharply pointed, and situated apically (♀; fig. 9B); retrolateral surface rugose, with cristulae (♂) and punctate. Patella slightly shorter (♂) or longer (♀) than tibia (table 1); prolateral surface with reddish macrosetae and vestigial (♂) or distinct (♀) spine situated distally on proventral margin; one spine at base of patellar apophysis; retrolateral surface with cristulae proximally (♂) and punctate. Patellar apophysis elongated, almost one-quarter carapace length, punctate and slender (♂) or shorter and robust (♀); prolateral margin with row of blunt denticles; retrolateral margin smooth (♂) or denticulate (♀), with subterminal macrosetae. Tibia longer than wide, laterally compressed; prodorsal surface with sparse row of denticles; prolateral surface sparsely punctate, with reddish macrosetae; proventral margin with two spines distally; fixed finger, dorsal and ventral margins each with row of denticles. Basitarsus (movable finger), dorsal and ventral margins each with serrate row of denticles; prolateral surface with several reddish macrosetae; apex bifid (♂).

Legs: Surfaces setose. Leg I, basitarsal and telotarsal tarsomeres I-VII gradually decreasing in length, with tarsomere I longest, tarsomere VIII two-thirds length of tarsomere I. Legs I-III coxae, lateral surfaces and IV, dorsal surface each with setose spiniform tubercles. Legs II-IV trochanters, dorsal and lateral surfaces with setose spiniform tubercles; femora dorsal surfaces with setose spiniform tubercles, prolateral surfaces with setose spiniform tubercles, retrolateral surfaces smooth; tibiae each with one ventrodistal spur; basitarsi each with two ventrodistal spurs. Leg I tibia with two trichobothria distally; legs II-IV tibiae each with one trichobothrium distally.

Opisthosoma: Tergites granular; I-V each with median longitudinal suture, weak and restricted to posterior margin on I and II, extending anteriorly on III; X (first segment of pygidium) with distinct lateral longitudinal sutures (pleuron); XII with pair of oval ommatoids posterolaterally. Sternite II (genital) with pair of oblong (♂) or lanceolate (♀) depressions submedially, posterolateral surfaces inflated (♂) (fig. 13B) or flat (♀) (fig. 13D), and posterior margin protruding markedly (♂) or slightly (♀) posteriorly into median lobe which overlaps sclerotized area in space between sternites II and III (♀); III linear (♂) or with pronounced emargination (♀) anteriorly, posterior margin with (♂) or without (♀) weak median suture, and median bulge with patch of reddish macrosetae (♂); IV undivided longitudinally; V-VII each with (♂) or without (♀) patch of fine macrosetae medially; VIII-IX surfaces smooth, asetose. Spermathecae seminal receptacles rounded, posteriorly directed (fig. 11A, B); spermathecal neck short, wide; aperture of uterus curved, with medial notch; dorsal atrium circular in dorsal aspect.

Sexual dimorphism: Adult males present several characters that differ from the females and immature stages. The pedipalps of the male are relatively elongated, unlike the pedipalps of the female, which are shorter and more robust (fig. 9A, B). A wide gap is present between spines S3 and S4 on the prodorsal margin of the pedipalp trochanter (fig. 7A), and AS is absent in the male whereas all spines on the prodorsal margin are evenly spaced and AS is present in the female. The retroventral spine on the pedipalp femur is short and situated proximally in the male, whereas it is longer and situated terminally in the female. The patellar apophysis of the male is more slender and elongated than that of the female. The posterolateral surfaces of sternite II are slightly inflated and the posteromedian margin protrudes markedly posteriorly in the male, whereas the posterolateral surfaces are flat, and the posteromedian margin protrudes slightly posteriorly in the female. Sternite III is linear anteriorly, its posteromedian margin protrudes slightly and bears a patch of macrosetae in the male, whereas sternite III is emarginate anteriorly, its posteromedian margin does not protrude, and a patch of macrosetae is absent in the female (fig. 13B, D).

Additional Material Examined: MEXICO: Morelos: Municipio Cuernavaca: Cuernavaca, 19.xi.2007, 1 ♂ (CNAN [Ur69]), 12. ix.1965, A. Manrique, 1 ♂ (CNAN [Ur23]), 28. ix.1997, M. Bravo, 1 ♀ (CNAN [Ur18]), 18. vii.2002, P. Berea, 2 ♀ (CNAN [Ur92, 115]), 2.X.2008, N. Chávez, 1 ♀ (CNAN [Ur73]), 1. xi.2011, N. Chávez, 1 ♂, 1 ♀, 2 juv. (CNAN [Ur127]); Cuernavaca, Santa Maria Ahuacatitlan suburb, 18°58′21.648″N 99°14′50.208″W, 1814 m, 1.viii.2013, R. Paredes, in house, 1 ♂ (CNAN [Ur139]), 24.ix.2015, R. Paredes, found dead in street, 1 ♂ (CNAN [RPL1606]); Cuernavaca, UAEM Campus, 15.xii.2015, 18°58′55.700″N 99°14′23.946″W, 1800 m, D. Barrales, R. Paredes, and A. Carlos, 5 juv. (CNAN [Ur178]).

Distribution: Known from Cuernavaca in the state of Morelos, Mexico (fig. 2).

Natural History: Mastigoproctus giganteus inhabits tropical deciduous forest, at elevations between 1380–1800 m, with temperature range of 10°-34° C and mean annual precipitation of 1200 mm (fig. 1E). This species is commonly found under large rocks and rotten logs, just prior to and during the rainy season. Specimens collected behaved aggressively, displaying with the pedipalps spread and the flagellum elevated; they did not hesitate to spray their vinegary repellent.

Remarks: Thelyphonus excubitor Girard, 1854, was described from a single female specimen of unknown provenance, although it was published in a report on the Expedition to the Red River in Louisiana Territory by Marcy et al. (1854). Wood (1863) synonymized T. excubitor with M. giganteus, where it has remained ever since. Louisiana Territory encompassed most of present-day Louisiana, as well as Arkansas, Oklahoma, Texas, and eastern New Mexico. Some of the spiders collected during that expedition and described by Girard (1854) indicate the date and approximate location (e.g., 17 May, between Camps 2 and 3) such that is possible to estimate where the types originated. There are no such annotations in the case of T. excubitor, unfortunately. Furthermore, Girard (1854) did not confine himself to describing specimens collected during that expedition: (1) the holotype of Scorpio boreus Girard, 1854, currently in Paruroctonus Werner, 1934, originated from the vicinity of the Great Salt Lake, Utah, and a smaller specimen originated from Eagle Pass, Texas, neither of which was visited during the Red River Expedition; (2) Scorpio californicus Girard, 1854, as the name indicates, was described from a specimen donated to the Smithsonian Institution from California: and (3) Scorpio sayi Girard, 1854, was described from a specimen from Pensacola, Florida. Thus, it is impossible to even narrow down the origin of T. excubitor to Louisiana Territory, as it may have come from anywhere. It might be argued that T. excubitor should be removed from that synonymy and declared a nomen dubium. However, in the spirit of nomenclatural stability promoted by the International Code of Zoological Nomenclature, it seems prudent to retain it in synonymy with M. giganteus, where it has been for the last 155 years.

Mastigoproctus giganteus floridanus Lönnberg, 1897: 189–191 (synonymized by Kraepelin, 1899: 224); McMonigle, 2013: fig. unnumbered, 100 (part).

Mastigoproctus giganteus: Kraepelin, 1899: 224; Banks, 1900: 422 (part); 1904: 143; Howard, 1919: 26; Ewing, 1928: 41–43, fig. 1; Savory, 1964: 166 (part); Muma, 1967: 21–23, fig. 16; Weygoldt, 1970: 1–7, figs, 1a, b, 2a–d, 3a–f, 4a–e; 1971: 137–141, figs, 1a, b, 2a, b, 3, 4, 5a–c, 6, pl. Ia–d, IIa–c, IIIa—c; Browder, 1973: 161; Jespersen, 1978: 241, figs. 21–23; Coddington et al, 1990: 11 (part); Corey and Stout, 1990: 169, 170; Crawford, 1990: 434, fig. 16.5 (part); Folkerts et al, 1993: 161; Punzo, 2001: 35–39, figs. 3, 4; 2005a: 684–690; 2005b: 172, 173; Beccaloni, 2009: 111 (part); Carrel and Britt, 2009: 500–502, figs. 1–4 (part); Kern and Mitchell, 2011: 2, 4, figs. 1–5 (part).

Type Material: U.S.A.: Florida: holotype ♀ ? (Swedish Museum of Natural History, Stockholm) [not examined].

Diagnosis: Mastigoproctus floridanus most closely resembles M. giganteus, from which it differs as follows. In the adult male of M. floridanus, spines S4 and S5 on the prodorsal margin of the pedipalp trochanter are blunt and a short, blunt subapical accessory spine (AS) is present whereas, in the adult male of M. giganteus, all spines on the prodorsal margin of the pedipalp trochanter are sharply pointed and an AS is absent.

Mastigoproctus floridanus also differs from M. cinteotl, sp. nov., and M. tohono, sp. nov., as follows. The carapace epistoma is visible in dorsal aspect in M. floridanus but not in M. cinteotl and M. tohono, and the lateral borders of the carapace are almost smooth in M. floridanus but strongly serrate in M. tohono. Spines S4 and S5 on the prodorsal margin of the pedipalp trochanter of the adult male are short and blunt in M. floridanus whereas S4 and S5 are longer and sharply pointed in M. cinteotl, and S4 is shorter in M. tohono.

Description; The following description is based on three males and two females.

Total length: Maximum length from anterior margin of carapace to posterior margin of opisthosomal segment XII (pygidium) in adult specimens 51.8 mm (♂) and 60.6 mm (♀) (table 2).

Color: Carapace dark reddish brown, anterior and lateral margins dark brown. Tergites I–IX dark reddish brown (♂) to reddish brown (♀), posterior and lateral borders darker. Sternites I and II light reddish brown mesally, margins reddish brown; III–IX and pygidium reddish brown (♀) to dark reddish brown (♂). Flagellum light reddish brown, segments with reddish-brown macrosetae. Pedipalp trochanter, femur, patella, and tibia dark reddish brown, mesal surfaces with few reddish macrosetae; patellar apophysis, fixed finger, and basitarsus blackish, with few reddish macrosetae. Legs I–IV reddish brown; II–IV coxae, ventral surfaces light reddish brown.

Carapace: Epistoma visible in dorsal aspect. Pair of strongly developed carinae anterolaterally, extending from lateral ocelli to two-thirds the distance to median ocular tubercle (fig. 10F). Three pairs of lateral ocelli with accessory translucent eyespot situated between anterior and posterior ocelli; anterior ocelli larger than median and posterior ocelli; anterior two pairs slightly separated from posterior pair by tubercle, distance between median and posterior ocelli 3× distance between anterior and median ocelli. Median ocular tubercle smooth, situated in anterior 10% of carapace (table 2); distance between ocelli almost 2× ocular diameter. Carapace surfaces rugose, tuberculate mediolaterally. Posterior fovea present, distinct.

Chelicerae: Retrolateral surface with stridulatory surface (plectrum), comprising approximately 20 long, stout (ca. 10× longer than wide), anteroventrally directed spiniform macrosetae (figs. 4C, 5C); mesal surface with few short, stout, anteroventrally directed spiniform macrosetae.

Pedipalps: Cuticle punctate. Coxa, retrolateral surface punctate; ventral surface smooth; coxal apophysis with one terminal spine; prodorsal surface with long, retroventrally directed macrosetae with cristulae, forming stridulatory surface (pars stridens) (fig. 6C). Trochanter longer than wide (♂), or sub equal (♀); retrodorsal surface punctate and setose; prodorsal margin with five terminal spines (S1–S5) and one subterminal accessory spine (AS), S1–S3 sharply pointed; S4, S5, and AS blunt, varying in size such that S3 > S2 > S4 > S5 ≥ S1 > AS (♂; fig. 7C) or S4 > S5 ≥ S3 > S2 > S1 ≥ AS (♀ ; fig. 7D); space between S3 and S4 equal to or greater than length of S3 (♂) or equal to space between S4 and S5 (♀); prolateral surface with several spiniform tubercles and reddish macrosetae (♂); proventral margin with two spines (♂). Femur laterally compressed (♂) or terete (♀), 2.1× (♀) to 2.5× (♂) longer than wide (table 2); prolateral surface with two spines, one prodorsal, short, sharply pointed, the other proventral, blunt, length one-quarter femur width (♂; fig. 9D) or short, sharply pointed, and situated apically (♀); retrolateral surface rugose, with sclerotized crests (♂) and punctate. Patella slightly shorter (♂) or longer (♀) than tibia (table 2); prolateral surface with reddish macrosetae, one vestigial (♂) or distinct (♀) spine situated distally on proventral margin and another vestigial spine situated two-thirds from proximal end of segment on proventral margin; one vestigial spine (♂) or two to three distinct spines (♀) at base of patellar apophysis; retrolateral surface sparsely punctate. Patellar apophysis elongated, almost one-quarter carapace length, smooth and slender (♂) or shorter and robust (♀); prolateral margin with row of blunt denticles; retrolateral margin smooth (♂) or denticulate (♀), with subterminal macrosetae. Tibia longer than wide, laterally compressed; prodorsal surface with sparse row of denticles; prolateral surface sparsely punctate, with reddish macrosetae; proventral margin with two spines distally; fixed finger, dorsal and ventral margins each with row of denticles. Basitarsus (movable finger), dorsal and ventral margins each with serrate row of denticles; prolateral surface with several reddish macrosetae; apex bifid (♂).

Legs: Leg I, basitarsal and telotarsal tarsomeres I–VII gradually decreasing in length, with tarsomere I longest, tarsomere VIII two-thirds length of tarsomere I. Legs I–III coxae, lateral surfaces and IV, dorsal surface each with setose spiniform tubercles. Legs II–IV trochanters, dorsal surfaces with setose spiniform tubercles; femora dorsal surfaces with setose spiniform tubercles, prolateral surfaces granular, retrolateral surfaces smooth; tibiae each with one ventrodistal spur; basitarsi each with two ventrodistal spurs. Leg I tibia with two trichobothria distally; legs II–IV tibiae each with one trichobothrium distally.

Opisthosoma: Tergites granular; I, median longitudinal suture restricted to anterior margin; II and III, each with median longitudinal suture restricted to posterior margin; X (first segment of pygidium) with distinct lateral longitudinal sutures (pleuron); XII with lateral pair of lanceolate ommatoids posterolaterally. Sternite II (genital) with pair of oblong (♂) or lanceolate (♀) depressions submedially, posterolateral surfaces inflated (♂) or flat (♀), and posterior margin protruding markedly (♂) or slightly (♀) posteriorly into median lobe which overlaps sclerotized area in space between sternites II and III (♀); III divided longitudinally (♂) or undivided (♀), linear (♂) or with pronounced emargination (♀) anteriorly; posterior margin with (♂) or without (♀) median bulge with patch of reddish macrosetae; IV undivided longitudinally; V–;VII each with (♂) or without (♀) patch of fine macrosetae medially; VIII–;IX surfaces smooth, asetose. Spermathecae seminal receptacles rounded, anteriorly directed (fig. 11C, D); spermathecal neck short, wide; aperture of uterus curved, with medial notch; dorsal atrium pentagonal in dorsal aspect.

Sexual dimorphism: Adult males present several characters that differ from the females and immature stages. The pedipalps of the male are relatively elongated, unlike the pedipalps of the female, which are shorter and more robust (fig. 9D). Spines S4, S5, and AS on the prodorsal margin of the pedipalp trochanter are blunt, and a wide gap is present between S3 and S4 in the male (fig. 7C, D) whereas these spines are sharply pointed and a gap is absent between S3 and S4 in the female. The retroventral spine on the pedipalp femur is short and situated proximally in the male, whereas it is longer and situated terminally in the female. The patellar apophysis of the male is more slender and elongated than that of the female. The posterolateral surfaces of sternite II are slightly inflated and the posteromedian margin protrudes markedly posteriorly in the male, whereas the posterolateral surfaces are flat, and the posteromedian margin protrades slightly posteriorly in the female. Sternite III is linear anteriorly, its posteromedian margin protrudes slightly and bears a patch of macrosetae in the male, whereas sternite III is emarginate anteriorly, its posteromedian margin does not protrade, and a patch of macrosetae is absent in the female (fig. 14B, D).

Additional Material Examined: U.S.A.: Florida: Johns Co.: St. Augustine, Anastasia Island, jct. SR 312 and SR 3 [29°51′08.92″N, 81°16′51.66″W], SE 1/4, Sec. 28, T 7 S, R 30 E, 1.vi.1981, K.A. Vliet, 1 ♂ (FSCA [Th4]). Lee Co.: Boca Grande [26°44′56.51″N 82°15′42.00″W], 12.ix.1974, E. Golby, 1 ♂ (FSCA [Th5]). Levy Co.: Bronson [29°26′49.91″N 82°38′31.14″W] 8.ix.2008, under bark, 1 ♂, 1 ♀ (AMNH); Willisten [29°23′14.89″N 82°26′48.37″W], summer 1965, log pile, 1 ♂ (FSCA [Th3]). Marion Co.: Ocala [29°11′13.91″N 82°08′24.33″W], 28.ix.1963, D. Bucklen and E.A. Graham, in house, 1 ♀ (FSCA [Th2]). Polk Co.: Winter Haven [28°01′19.85″N 81°43′59.21″W], 20.xii.1954, M. Muma, under board on ground, 1 ♀ (FSCA [Th1]).

Distribution: Known only from the state of Florida in the United States (fig. 2).

Natural History: Mastigoproctus floridanus inhabits subtropical scrub forest, at elevations between 10–100 m, with a temperature range of 4°–38° C and mean annual precipitation of 1500 mm. According to Lönnberg (1897) and Muma (1967), this species is often found under rotten logs and other debris on the surface of the ground and occasionally in houses.

Thelyphonus mexicanus Butler, 1872: 201, fig. 1.

Thelyphonus (?) mexicanus: Tarnani, 1890: 538.

Mastigoproctus giganteus mexicanus: Pocock, 1902a: 48; Mello-Leitão, 1931: 27; Harvey, 2003: 67; Barrales-Alcalá et al., 2016: 26, 46 (part); McMonigle, 2013: 100, fig. unnumbered, 100 (part).

Type Material: MEXICO: holotype ♂ (Natural History Museum, London) [photographs examined].

Diagnosis: Mastigoproctus mexicanus resembles M. vandevenderi, sp. nov., from which it differs as follows. Adult M. mexicanus are densely setose and reddish in color whereas adult M. vandevenderi are sparsely setose and brownish. Spine S3 is longer than the other spines on the prodorsal margin of the pedipalp trochanter of the adult male in M. mexicanus whereas spines S3 and S4 are equal in M. vandevenderi. The tubercles on the retrolateral surface of the pedipalp femur are straight and digitiform in M. mexicanus but curved and cup shaped in M. vandevenderi. The seminal receptacles of the spermathecae are swollen, ob ovate and anteriorly directed in M. mexicanus but narrow, triangular, and posteriorly directed in M. vandevenderi.

Description: The following description is based on one male and two females.

Total length: Maximum length from anterior margin of carapace to posterior margin of opisthosomal segment XII (pygidium) in adult specimens 55.0 mm (♂) and 50.1 mm (♀) (table 2).

Color: Carapace reddish, anterior margin reddish brown, lateral margins dark reddish brown, median ocular tubercle dark reddish brown. Tergites I–IX reddish, posterior and lateral margins dark reddish. Sternites I and II reddish; III–IX and pygidium reddish brown. Pedipalp trochanter, femur, patella and tibia, dark reddish brown, mesal surfaces with several dark reddish macrosetae; patellar apophysis, fixed finger and basitarsus blackish, with reddish macrosetae. Legs I–IV reddish brown; II–IV coxae, ventral surfaces reddish.

Carapace: Epistoma visible in dorsal aspect. Pair of strongly developed carinae anterolaterally, extending from lateral ocelli to two-thirds the distance to median ocular tubercle (fig. 10B). Three pairs of lateral ocelli with accessory translucent eyespot situated between anterior and posterior ocelli; anterior ocelli almost equal to median and posterior ocelli; anterior two pairs slightly separated from posterior pair by tubercle, distance between median and posterior ocelli 6× distance between anterior and median ocelli. Median ocular tubercle smooth, situated in anterior 10% of carapace (table 2); distance between ocelli almost 1.5× ocular diameter. Carapace surfaces granular, tuberculate mediolaterally, and with sclerotized crests between median ocular tubercle and anterior margin. Posterior fovea present, distinct.

Chelicerae: Retrolateral surface with stridulatory surface (plectrum), comprising approximately 30 short, stout (ca. 7× or 8× longer than wide), anteroventrally directed spiniform macrosetae (figs. 4D, 5D); mesal surface with few short, stout, anteroventrally directed spiniform macrosetae.

Pedipalps: Cuticle punctate and tuberculate, with cristulae. Coxa, retrolateral surface with cristulae; ventral surface rugose; coxal apophysis with one terminal spine; prodorsal surface with long, retroventrally directed macrosetae inserted in cristulae, forming stridulatory surface (pars stridens) (fig. 6D). Trochanter longer than wide (♂), or subequal (♀); retrodorsal surface tuberculate with long, straight cristulae (♂) or punctate (♀); prodorsal margin with five terminal spines (S1–S5) and one subterminal accessory spine (AS), varying in size such that S3 > S4 ≥ S2 ≥ S5 > S1 > AS (♂; fig. 7E) or S4 > S5 ≥ S3 > S2 > S1 > AS (♀; fig. 7F); space between S4 and S3 subequal to length of S3 (♂) or sub equal to space between S4 and S5 (♀); prolateral surface with several spiniform tubercles and reddish macrosetae (♂); proventral margin with two spines (♂). Femur laterally compressed (♂) or terete (♀), 2× (♀) to 2.5× (♂) longer than wide (table 2); prolateral surface with two spines, one prodorsal, short, sharply pointed, the other proventral, blunt, length one-fifth femur width (♂; fig. 9E) or short, sharply pointed, and apical (♀); retrolateral surface with sharply pointed digitiform tubercles (♂) or short tubercles proximally (♀). Patella slightly longer (♂) or shorter (♀) than tibia (table 2); prolateral surface with several reddish macrosetae, one spine (♂) or one to two spines (♀) situated distally on proventral margin; one vestigial (♂) or distinct (♀) spine at base of patellar apophysis; retrolateral surface tuberculate proximally. Patellar apophysis elongated, almost one-quarter carapace length, smooth and slender (♂) or shorter and robust (♀); prolateral margin with row of blunt, pointed denticles; retrolateral margin smooth (♂) or denticulate (♀), with subterminal macrosetae. Tibia laterally compressed; prodorsal surface with sparse row of denticles; prolateral surface sparsely punctate, with reddish macrosetae; proventral margin with two spines distally; fixed finger, dorsal and ventral margins each with row of denticles. Basitarsus (movable finger), dorsal and ventral margins each with serrate row of denticles; prolateral surface with several reddish macrosetae; apex bifid (♂).

Legs: Leg I, basitarsal and telotarsal tarsomeres I–VII gradually decreasing in length, with tarsomere I longest, tarsomere VIII four-fifths length of tarsomere I. Legs I–III coxae, lateral surfaces and IV, dorsal surface each with setose spiniform tubercles. Legs I–IV trochanters, dorsal and lateral surfaces with setose spiniform tubercles; femora dorsal and ventral surfaces with setose spiniform tubercles, situated proximally on I, II–IV, retroventral surfaces each with setose spiniform tubercle terminally, with macroseta inserted subterminally; tibiae each with one ventrodistal spur; basitarsi each with two ventrodistal spurs. Leg I tibia with two trichobothria distally; legs II-IV tibiae each with one trichobothrium distally.

Opisthosoma: Tergites almost smooth with few dark macrosetae; I without median longitudinal suture; II with median longitudinal suture, extending from anterior margin to midsegment; tergites III—IX undivided; X (first segment of pygidium) with distinct lateral longitudinal sutures (pleuron); XII with pair of lateral, ovobate ommatoids posterolaterally. Sternite II (genital) with pair of V-shaped (♂) or lanceolate (♀) depressions submedially, posterolateral surfaces inflated (♂) or flat (♀), and posterior margin protruding markedly (♂) or slightly (♀) posteriorly into median lobe, emarginate medially and overlapping sclerotized area in space between sternites II and III (♀); III divided longitudinally (♂) or undivided (♀), linear (♂) or with pronounced emargination (♀) anteriorly, posterior margin with (♂) or without (♀) median bulge with patch of reddish macrosetae; IV undivided longitudinally; V with (♂) or without (♀) patch of fine macrosetae medially; VI–VIII surfaces smooth, with few dark macrosetae (♂); IX surface smooth, asetose. Spermathecae seminal receptacles obovate, anteriorly directed (fig. 11E, F); spermathecal neck short, narrow; aperture of uterus curved, with medial notch; dorsal atrium pentagonal in dorsal aspect.

Sexual dimorphism: Adult males present several characters that differ from the females and immature stages. The pedipalps of the male are relatively elongated (fig. 9E), unlike the pedipalps of the female, which are shorter and more robust. A wider gap is present between spines S3 and S4 than between other spines on the prodorsal margin of the pe dip alp trochanter in the male (fig. 7E, F) whereas all spines along the prodorsal margin are evenly spaced in the female. Long, digitiform tubercles are present on the retrolateral surface of the femur in the male, whereas short tubercles and cristulae are present on the retrolateral surface of the female. The retroventral spine on the pedipalp femur is short and situated proximally in the male, whereas it is longer and situated distally in the female. The patellar apophysis is slender and elongated in the male, whereas it is short and stout in the female. The posterolateral surfaces of sternite II are slightly inflated in the male, but flat in the female. Sternite III is not emarginate anteriorly and its posterior margin exhibits a posteromedian bulge with a patch of macrosetae in the male, whereas sternite III is conspicuously emarginate anteriorly, its posteromedian margin does not protrude, and a patch of macrosetae is absent in the female (fig. 15B, D).

Additional Material Examined: MEXICO: Aguascalientes: Municipio Calvillo: 3 km E Presa Alamitos, 21°44′06.468″N 102°41′51.108″W, 2,440 m, 24.vii.2012, D. Barrales, G. Contreras, O. Francke, and A. Valdez, oak forest, 1 ♂, 1 5,1 sub ad. ♂, 9 juv. (CNAN [Ur57]).

Distribution: Known only from the vicinity of Presa Alamitos, in the municipality of Calvillo, Aguascalientes, Mexico (fig. 2).

Natural History: Mastigoproctus mexicanus inhabits oak forest, at elevations of 2000–2400 m, with a temperature range of 18°–22° C and mean annual precipitation of 660 mm. Specimens were collected under large rocks, and it was not unusual to find juveniles and adults together under the same shelter. The species is fairly abundant in the area. No aggressive behavior was observed.

Mastigoproctus giganteus scabrosus Pocock, 1902a: 48; Mello-Leitão, 1931: 28; Harvey, 2003: 67; Zárate-Gálvez and Chame-Vázquez, 2007: 393–395 (misidentification); McMonigle, 2013: 100, fig. unnumbered, 100 (part); Barrales-Alcalá et al, 2016: 26, 46, fig. 3A–D.

Mastigoproctus giganteus scatrosus: Franganillo, 1936: 147.

Type Material; MEXICO; Oaxaca: Holotype♂(Natural History Museum, London) [photographs examined].

Diagnosis; Mastigoproctus scabrosus, stat. nov., is among the most conspicuous North American species of Mastigoproctus and may be distinguished from M. mexicanus and M. vandevenderi, sp. nov., both of which also exhibit tubercles on the retrolateral surface of the pedipalp femur, as follows. Mastigoproctus scabrosus is sparsely setose whereas M. mexicanus is densely setose. A cheliceral-coxal stridulatory organ is absent in M. scabrosus, but present in M. mexicanus and M. vandevenderi. Spines S4 and S5 on the prodorsal margin of pedipalp trochanter of the adult male are fused in M. scabrosus, but separated in M. mexicanus and M. vandevenderi. The terminal spiniform tubercle on the retroventral surfaces of the femora of legs II-IV is conical in M. scabrosus whereas it is more tubular (digitiform) in M. vandevenderi and M. mexicanus.

Description; The following description is based on three males and one female.

Total length: Maximum length from anterior margin of carapace to posterior margin of opisthosomal segment XII (pygidium) in adult specimens 73.7 mm (♂) and 64.2 mm (♀) (table 3).

Color. Carapace dark reddish brown, anterior margin blackish, lateral margins dark brown. Tergites I–IX dark reddish brown, posterior and lateral margins blackish. Sternites I and II reddish brown; III–IX and pygidium dark reddish brown. Flagellum dark brown, segments with reddishbrown macrosetae. Pedipalp trochanter, femur, patella, and tibia dark brown, mesal surfaces with few reddish macrosetae; patellar apophysis, fixed finger and basitarsus, blackish, with reddish macrosetae. Legs I–IV dark reddish brown; II–IV coxae, ventral surfaces reddish brown.

Carapace: Epistoma visible in dorsal aspect. Pair of strongly developed carinae anterolaterally, extending from lateral ocelli to two-thirds the distance to median ocular tubercle (fig. 10G). Three pairs of lateral ocelli with accessory translucent eyespot situated between anterior and posterior ocelli; anterior ocelli larger than median and posterior ocelli; anterior two pairs slightly separated from posterior pair by tubercle, distance between median and posterior ocelli 10× distance between anterior and median ocelli. Median ocular tubercle rugose, situated in anterior 10% of carapace (table 3); distance between ocelli almost 2× ocular diameter. Carapace surfaces densely granular, tuberculate mediolaterally. Posterior fovea present, distinct.

Chelicerae: Retrolateral surface without stridulatory surface; mesal surface with reddish macrosetae (figs. 4E, 5E).

Pedipalps: Cuticle punctate and tuberculate with cristulae. Coxa, retrolateral surface with cristulae; ventral surface rugose; coxal apophysis with one terminal spine; prodorsal surface smooth, with macrosetae (fig. 6E). Trochanter longer than wide; retrodorsal surface tuberculate; prodorsal margin with five terminal spines (S1– S5) and one subterminal accessory spine (AS), varying in size such that S4 > S3 > S2 > S5 > S1 > AS (♂ fig. 7G) or S4 > S3 > S5 > S2 > S1 > AS (♀ ; fig. 7H); spaces between S2 and S3 equal to or greater than length of S2 and between S3 and S4 equal to or greater than length of S3 (♂ fig. 7G) or spines evenly spaced (♀); prolateral surface with several spiniform tubercles and reddish macrosetae (♂); proventral margin with two spines (♂). Femur laterally compressed (♂) or terete (♂), 2× (♀) to almost 3× (♂) longer than wide (table 3); prolateral surface with two spines, one prodorsal, short, blunt (♂) or sharply pointed (♀), the other proventral, sharply pointed, length almost one-third femur width (♂; fig. 9C) or short, sharply pointed, and situated apically (♀); retrolateral surface rugose, with short, blunt (♀) or long, sharply pointed (♂) tubercles. Patella slightly shorter (♂) or longer (♀) than tibia (table 3); prolateral surface with reddish macrosetae, one vestigial (♂) or distinct (♀) spine situated distally on proventral margin; one or two spines (♂) or one or three distinct spines (♀) at base of patellar apophysis; retrolateral surface with short tubercles (♂) or punctate (♀). Patellar apophysis elongated, almost one-quarter carapace length, smooth and slender (♂) or shorter and robust (♀); prolateral margin with row of blunt denticles; retrolateral margin smooth (♂) or denticulate (♀), with subterminal macrosetae. Tibia longer than wide, laterally compressed; prodorsal surface with sparse row of denticles; prolateral surface with cristulae and reddish macrosetae; proventral margin with two spines distally; fixed finger, dorsal and ventral margins each with row of denticles. Basitarsus (movable finger), dorsal and ventral margins each with serrate row of denticles; prolateral surface with several reddish macrosetae; apex bifid (♂).

Legs: Leg I, femur with sclerotized crests proximally; basitarsal and telotarsal tarsomeres I–VII gradually decreasing in length, with tarsomere I longest, tarsomere VIII two-thirds length of tarsomere I. Legs I–III coxae, lateral surfaces and IV, dorsal surface each with setose spiniform tubercles. Legs I–IV trochanters, dorsal and lateral surfaces with setose spiniform tubercles. Legs II–IV femora dorsal surfaces with setose spiniform tubercles, retroventral surfaces each with setose spiniform tubercle terminally, with macroseta inserted terminally, prolateral surfaces granular, retrolateral surfaces smooth; tibiae each with one ventrodistal spur; basitarsi each with two ventrodistal spurs. Leg I tibia with two trichobothria distally; legs II-IV tibiae each with one trichobothrium distally.

Opisthosoma: Tergites granular; I with median longitudinal suture; II with median longitudinal suture extending from anterior margin to midsegment; III with faint longitudinal suture; tergites IV–IX undivided; X (first segment of pygidium) with distinct lateral longitudinal sutures (pleuron); XII with pair of ovobate ommatoids postero-laterally. Sternite II (genital) with pair of V-shaped (♂) or lanceolate (♀) depressions submedially, posterolateral surfaces inflated (♂) or flat (♀), and posterior margin protrading markedly (♂) or slightly (♀) posteriorly into median lobe, emarginate medially and overlapping sclerotized area in space between sternites II and III (♀); III divided longitudinally (♂) or undivided (♀), linear (♂) or with pronounced emargination (♀) anteriorly, posteromedial margin with (♂) or without (female;) median bulge with patch of reddish macrosetae; IV divided longitudinally (♂) or undivided (♀); V with (♂) or without (♀) patch of fine macrosetae medially; VI–IX surfaces smooth, asetose. Spermathecae seminal receptacles rounded, anteriorly directed (fig. 11G, H); spermathecal neck short, narrow; aperture of uterus straight, with medial notch; dorsal atrium triangular in dorsal aspect.

Sexual dimorphism: Adult males present several characters that differ from the females and immature stages. The pedipalps of the male are relatively elongated (fig. 9C), unlike the pedipalps of the female, which are shorter and more robust. On the prodorsal margin of the pedipalp trochanter, two wide gaps are present between spines S2 and S3 and between spines S3 and S4, and spines S4 and S5 are fused in the male (figs. 7G, H, 9C), whereas all spines along the prodorsal margin are evenly spaced, and spines S4 and S5 are separated in the female. Long tubercles are present on the retrolateral surface of the femur in the male, whereas short tubercles and sclerotized crests are present on the retrolateral surface of the female. The retroventral spine on the pedipalp femur is short and situated proximally in the male, whereas it is longer and situated terminally in the female. The patellar apophysis of the male is more slender and elongated than that of the female. The posterolateral surfaces of sternite II are slightly inflated in the male but flat in the female. Sternite III is not emarginate anteriorly in the male, and exhibits a posteromedian bulge with a patch of macrosetae in the male, whereas sternite III is emarginate anteriorly, its posteromedian margin does not protrude, and a patch of macrosetae is absent in the female (fig. 16B, D).

Additional Material Examined: MEXICO: Veracruz: Municipio Atoyac: Atoyac, outside Cueva de Atoyac, 18°55′ 18.663″N 96°45′54.687″W, 500 m, 18.ii.2017, D. Barrales, G. Contreras, and R. Monjaraz, 1 juv. (CNAN [Ur169]); Atoyac, Rancho San Fermín, 18°54′04.593″N 96°48′19.760″W, 549 m, 18.iv.2017, A. Ramírez, 1♂(CNAN [Ur176]), 18°54′27.226″N 96°48′40.734″W, 568 m, 18.V.2017, P. López, 1♀(CNAN [Ur175]). Municipio Catemaco: Catemaco [18°25′17.02″N 95°06′47.40″W], 1964, W.F. Pyburn, 1♂(CAS), viii.1965, A. Hoffmann, 1♂(FCUNAM). Municipio Fortín de las Flores: Canyon near Fortín [18°54′00.72″N 97°00′37.53″W], 17.xii.1948, G. Rabago, 1♂(CAS). Municipio Los Tuxtlas: San Andrés Tuxtla, Estación de Biología Tropical Los Tuxtlas, 18°35′05.64″N, 95°04′26.16″W, 148 m, 1.vi.2017, M. Madora, 1♀(CNAN [Ur174]). Municipio Puente Nacional: Puente Nacional [19°19′46.56″N 96°28′57.65″W], viii.1947, 1♂(AMNH), viii.2002, P. Berea, 1♀(CNAN [Ur70]).

Distribution: Known from the municipalities of Atoyac, Cordova, Los Tuxtlas, Playa Vicente and Puente Nacional, in the state of Veracruz, Mexico (fig. 2). Playa Vicente, in Veracruz, where the paratype was collected, is near the border with the state of Oaxaca, so the holotype, which is from an indefinite location in that state, may have originated in that general vicinity.

Natural History: Mastigoproctus scabrosus inhabits tropical deciduous forest and the tropical rainforest, at elevations of 50–800 m, with temperatures of 6°–35° C and mean annual precipitation of 721800 mm (fig. 1F). Specimens are active in the rainy season, becoming inactive during the dry season. Adults often hide in rotten logs, whereas juveniles are commonly found under large stones.

Mastigoproctus giganteus: Reddell and Mitchell, 1971a: 145, fig. 18; 1971b: 185; Reddell and Elliott, 1973: 183; Rowland and Reddell, 1976: 3, 4; Cokendolpher and Bryce, 1980: 18; Reddell, 1981: 124; Palacios et al, 2014–2015: 32.

Type Material: MEXICO: Tamaulipas: Municipio Gómez Farías: Holotype♂(CNAN T1149), subad.♂paratype (CNAN T01040), 1 km N Mirador Camino de Alta Cima, 23°03′12.78″N 99°10′45.32″W, 763 m. 20.iv.2016, J. Arreguín, G. Contreras, D. Guerrero, R. Monjaraz, G. Montiel and J. López; paratype ♂, paratype♀(AMNH), 8 mi. NW Gómez Farías, 1–5. vi. 1964, J. Reddell, D. McKenzie, and L. Manire.

Etymology: This new species is named after the Aztec god Cinteotl, responsible for providing the first corn seeds to their ancestors. The Mexican state of Tamaulipas was an important center for the domestication of corn (McClung de Tapia et al., 2001). The name is a noun in apposition.

Diagnosis: Mastigoproctus cinteotl, sp. nov., resembles M. giganteus and M. floridanus, from which it differs as follows. Spines S3 and S4 on the prodorsal margin of the pedipalp trochanter are equal, and S4 and S5 are subequal in M. cinteotl, whereas S3 and S4 are unequal, and S5 shorter than S4, in M. giganteus; and S3 is longer than S4, and S4 and S5 subequal, in M. floridanus. The punctures on the retrolateral surface of the pedipalp femur are markedly cristulate, providing a rugose texture in M. cinteotl, whereas the punctures are weakly cristulate in M. floridanus. Sternite V is smooth in the adult male of M. cinteotl, but possesses a patch of fine macrosetae in M. giganteus and M. floridanus.

Description: The following description is based on two males and one female.

Total length: Maximum length from anterior margin of carapace to posterior margin of opisthosomal segment XII (pygidium) in adult specimens 65.8 mm (♂) and 53.9 mm (♀) (table 4).

Color. Carapace dark brown, anterior margin blackish. Tergites I–IX dark brown, posterior and lateral margins black. Sternites I–VIII dark reddish brown, lateral margins blackish. Sternite IX blackish, lateral and posterior margins black. Pygidium, dorsal and ventral surfaces dark reddish brown. Flagellum dark brown, segments with dark brown macrosetae. Pedipalp trochanter dorsal and ventral surfaces dark brown, almost black, prolateral surface with reddish macrosetae. Pedipalp femur and patella dark brown, almost black, patellar apophysis black; tibia, dorsal and ventral surfaces dark brown, mesal surfaces with reddish macrosetae; fixed finger and basitarsus black. Leg I dark reddish brown; II–IV, coxae, ventral surfaces reddish brown, trochanter, femora, patellae, tibiae, basitarsi and telotarsi, dorsal and ventral surfaces dark reddish brown, lateral surfaces reddish brown.

Carapace: Epistoma visible in dorsal aspect. Pair of strongly developed carinae anterolaterally, extending from lateral ocelli to two-thirds the distance to median ocular tubercle (fig. 10C). Three pairs of lateral ocelli with accessory translucent eyespot situated between anterior and posterior ocelli; anterior ocelli larger than median and posterior ocelli; anterior two pairs slightly separated from posterior pair by tubercle, distance between median and posterior ocelli 10× distance between anterior and median ocelli. Median ocular tubercle smooth, situated in anterior 10% of carapace (table 4); distance between ocelli 2x ocular diameter. Carapace anterior and medial surfaces rugose, mediolateral surfaces tuberculate, other surfaces granular. Posterior fovea present, distinct.

Chelicerae: Retrolateral surface with stridulatory surface (plectrum), comprising approximately 20 short, stout (ca. 8x longer than wide), anteroventrally directed spiniform macrosetae (figs. 4F, 5F); mesal surface with few short, stout, anteroventrally directed spiniform macrosetae.

Pedipalps: Cuticle punctate with cristulae. Coxa, retrolateral surface rugose; ventral surface smooth and densely punctate; coxal apophysis with one terminal spine; prodorsal surface with long, proventrally directed macrosetae inserted in cristulae, forming stridulatory surface (pars stridens) (fig. 6F). Trochanter wider than long (♂) or longer than wide (♀); retrodorsal surface with cristulae (♂), punctate; prodorsal margin with five terminal spines (S1–S5) and one subterminal accessory spine (AS), all sharply pointed, varying in size such that S3 ≥ S4 ≥ S5 > S2 > S1 > AS (♂; fig. 8A) or S4 > S5 > S3 > S2 > S1 > AS (♀; fig. 8B); space between S3 and S4 equal to or greater than length of longest spine (♂) or equal to space between S4 and S5 (♀); prolateral surface with several spiniform tubercles and reddish macrosetae (♂); proventral margin with two spines (♂). Femur laterally compressed (♂) or terete (♀), 2.5x (♀) to 3x (♂) longer than wide (table 4); prolateral surface with two spines, one prodorsal, short, sharply pointed, the other proventral, sharply pointed, length one-third to one-fifth femur width (♂; fig. 9F) or short, sharply pointed, and situated apically (♀); retrolateral surface markedly punctate, with distinct cristulae (♂). Patella slightly shorter (♂) or longer (♀) than tibia (table 4); prolateral surface with reddish macrosetae, one vestigial (♂) or distinct (♀) spine situated distally on proventral margin; one short, blunt spine (♂) or one or two sharp spines (♀) at base of patellar apophysis; retrolateral surface shallowly punctate. Patellar apophysis elongated, almost one-quarter carapace length, smooth and slender (♂) or shorter and robust (♀); prolateral margin with row of blunt (♂) or sharply pointed (♀) denticles; retrolateral margin smooth (♂) or sparsely denticulate (♀), with subterminal macrosetae. Tibia laterally compressed (♂) or terete (♀); pro dorsal surface with sparse row of denticles; prolateral surface with reddish macrosetae; proventral margin with two spines distally; fixed finger, dorsal and ventral margins each with row of denticles. Basitarsus (movable finger), dorsal and ventral margins each with serrate row of denticles; prolateral surface with several reddish macrosetae; apex bifid (♂)•

Legs: Leg I, basitarsal and telotarsal tarsomeres I–VII gradually decreasing in length, with tarsomere I longest, tarsomere VIII two-thirds length of tarsomere I. Legs I–III coxae, lateral surfaces and IV, dorsal surface each with setose spiniform tubercles. Legs II–IV trochanters, dorsal and lateral surfaces with setose spiniform tubercles. Legs I–IV femora dorsal surfaces with setose spiniform tubercles, situated proximally on I, II–IV, retroventral surfaces each with setose spiniform tuber- cle terminally, with macroseta inserted terminally; lateral surfaces smooth; tibiae each with one ventrodistal spur; basitarsi each with two ventrodistal spurs. Leg I tibia with two trichobothria distally; legs II–IV tibiae each with one trichobothrium distally.

Opisthosoma: Tergites finely granular, more coarsely so along posterior margins; I with median longitudinal suture extending from midsegment to posterior margin; II with weak median longitudinal suture; III with median longitudinal suture extending from anterior margin to anterior third of segment; other tergites undivided; X (first segment of pygidium) with distinct lateral longitudinal sutures (pleuron); XII with pair of obovate ommatoids posterolaterally. Sternite II (genital) with pair of V-shaped (♂) or lanceolate (♀) depressions submedially, posterolateral surfaces inflated (♂) or flat (♀), and posteromedian margin protruding markedly (♂) or slightly (♀) posteriorly into median lobe, emarginate medially and overlapping sclerotized area in space between sternites II and III (♀); III divided longitudinally (♂) or undivided (♀), linear (♂) or with pronounced emargination (♀) anteriorly, posterior margin with (♂) or without (♀) patch of reddish macrosetae on posteromedian bulge; IV divided longitudinally (♂) or undivided (♀); V–IX surfaces smooth, asetose. Spermathecae seminal receptacles oblong, anteriorly directed (fig. 12A, B); spermathecal neck short, wide; aperture of uterus rounded, with medial notch; dorsal atrium triangular in dorsal aspect.

Sexual dimorphism: Adult males present several characters that differ from the females and immature stages. The pedipalps of the male are relatively elongated (fig. 9F), unlike the pedipalps of the female, which are shorter and more robust. A wider gap is present between spines S3 and S4 than between the other spines on the prodorsal margin of the pedipalp trochanter in the male, whereas all spines along the prodorsal margin are evenly spaced in the female (fig. 8A, B). The retrolateral surface of the pedipalp femur is punctate, with cristulae in the male (fig. 9F) but punctate and smooth, without cristulae, in the female. The patellar apophysis of the male is more slender and elongated than that of the female. The posterolateral surfaces of sternite II are slightly inflated in the male, but flat in the female. Sternite III is not emarginate anteriorly and exhibits a posteromedian bulge with a patch of macrosetae in the male, whereas it is emarginate anteriorly, its posteromedian margin does not protrude, and a patch of macrosetae is absent in the female (fig. 17B, D).

Additional Material Examined: MEXICO: Tamaulipas: Municipio Gómez Farías: Altamira, 5.Vii.1999, G. Montiel, 2♂(CNAN [Ur43]); Reserva El Cielo, surroundings of Centro Interpretativo Ecológico, 23°03′56.52″N 99°10′08.220″W, 343 m, 22.iv.2016, J. Arreguín, et al., tropical semideciduous forest, 1 subad.♂(CNAN [Ur155]).

Distribution: Known from the vicinity of El Cielo Protected Area in the municipality of Gómez Farías, Tamaulipas, Mexico (fig. 2). Populations from the Lower Rio Grande Valley in Texas, are probably conspecific based on one available sequence of the mitochondrial Cytochrome Oxidase I (COI) gene. Some specimens from western Texas, the Big Bend area, and southern New Mexico are probably not conspecific, but no adult males were available for examination.

Natural History: Mastigoproctus cinteotl inhabits the tropical semideciduous forest, at elevations of 300–800 m, with temperatures of 15°–27° C and mean annual precipitation of 670–3500 mm (fig. 2G). Specimens collected in April 2016 were found alone under large rocks and no juveniles were observed, suggesting that the breeding season occurs at another time of the year. Specimens were passive when collected, despite the warm temperatures. When handled, they sprayed a very aromatic secretion. Punzo and Reeves (2001) reported differences in the mating behavior of specimens identified as Mastigoproctus giganteus from Florida and Texas, reflecting differences between M. floridanus and this new species.

Mastigoproctus giganteus: Wood, 1863: 374; Kraepelin, 1899: 224 (part); Banks, 1900: 422 (part); Comstock, 1913: 19, fig. 14; 1952: 5, fig. 1 (part); Eisner et al., 1961: 272–297, figs. 1–22; Savory, 1964: 166 (part); Lawrence, 1969: 125, 130; Ahearn, 1970: 339–351, figs. 1–6; Crawford and Cloudsley-Thompson, 1971: 99–106, fig. 1; Cloudsley-Thompson, 1975: 266, 273, 274; Muma, 1975: 262; Crawford, 1981: 21, 35, 36, 56, 59, 78, 86, 134, 137, 215, fig. 12c; Vasta and Marchalonis, 1983: 160, 161, 165; Vasta and Cohen, 1984: 334–340; Cloudsley-Thompson, 1986: 30; Barnes, 1987: 508, figs. 13–15, 16a, b; Coddington et al., 1990: 11 (part); Crawford, 1990: 434, fig. 16.5 (part); Shultz, 1991: 13–31, figs. 5c, 7–11; 1992b: 314–328, figs, 1a, 2, 3; 1993: 335– 365, figs. 1, 2a–c, 3a, b, 4a–d, 5a, b, 6, 7a, b, 8, 9a, b; Schmidt et al., 2000: 443–450; Schmidt, 2003: 11; Punzo, 2007: 66–72; Beccaloni, 2009: 111 (part); Carrel and Britt, 2009: 500–502, figs. 1–4 (part); Kern and Mitchell, 2011: 2, 4, figs. 1–5 (part); Hembree, 2013: 141–162 (part); McMonigle, 2013: 100, fig. unnumbered (part); Smith and Courter, 2015: 2603–2618, fig. 5; Monjaraz-Ruedas et al., 2016: 118–134, fig. 6A, B (part).

Type Material: U.S.A.: Arizona: Cochise Co.: Holotype ♂ (AMNH), Portal [31°54′48.23″N 109°08′39.67″W], 30.viii. 1969, W.J. Gertsch; paratype ♀ (AMNH), Portal, 3.ix.1965, J. Jansen; 2 ♀ paratypes (AMNH, CNAN T1151), Southwestern Research Station, 5 mi. W Portal, [31°53′2.62″N 109°12′21.13″W], xi.1955, M.A. Cazier and E. Ordway.

Etymology: This new species is named after the Tohono O'odham Native American people from southern Arizona and northern Sonora, Mexico, who have developed a deep relationship with the environment. The name is a noun in apposition.

Diagnosis: Mastigoproctus tohono, sp. nov., resembles M. giganteus and M. floridanus, from which it differs as follows. The carapace epistoma is not visible in dorsal aspect in M. tohono, but is visible in M. giganteus and M. floridanus. Spine S4 on prodorsal margin of the pedipalp trochanter of the adult male is blunt and shorter than the other spines on the prodorsal margin in M. tohono, whereas spine S4 is longer than spine S5 in M. giganteus and M. floridanus, and sharply pointed in M. giganteus. The punctures on the retrolateral surface of the pedipalp femur are weakly cristulate in M. tohono, but markedly cristulate in M. giganteus and not cristulate in M. floridanus.

Description: The following description is based on one male and three females.

Total length: Maximum length from anterior margin of carapace to posterior margin of opisthosomal segment XII (pygidium) in adult specimens 56.5 mm (♂) and 59.4 mm (♀) (table 4).

Color: Carapace dark reddish brown, with median lateral edges darker. Tergites I–IX reddish brown, lateral margins dark reddish brown. Sternites I–VIII reddish brown, lateral margins dark reddish brown. Sternite IX dark reddish brown. Pygidium, dorsal and ventral surfaces reddish brown. Flagellum reddish brown, segments with reddish macrosetae. Pedipalp trochanter, dorsal and ventral surfaces dark reddish brown, with reddish macrosetae anteriorly Pedipalp femur and patella dark reddish brown, almost black, patellar apophysis black; tibia, dorsal and ventral surfaces dark reddish brown, mesal surfaces with reddish macrosetae; fixed finger and basitarsus black. Leg I, femur and patella dark reddish brown, tibia, basitarsus and telotarsus reddish brown; legs II– IV dark reddish brown.

Carapace: Epistoma not visible in dorsal aspect. Pair of strongly developed carinae anterolaterally, extending from lateral ocelli to two-thirds the distance to median ocular tubercle (fig. 10H). Three pairs of lateral ocelli with accessory translucent eyespot situated between anterior and posterior ocelli; anterior ocelli larger than median and posterior ocelli; anterior two pairs slightly separated from posterior pair by tubercle, distance between median and posterior ocelli 6× distance between anterior and median ocelli. Median ocular tubercle smooth, situated in anterior 10% of carapace (table 4); distance between ocelli 2× ocular diameter. Carapace anterior and medial surfaces smooth, other surfaces granular. Posterior fovea present, distinct.

Chelicerae: Retrolateral surface with stridulatory surface (plectrum), comprising approximately 50 long, slender (ca. 15-25× longer than wide), anteroventrally directed macrosetae (figs. 4G, 5G); mesal surface with few long, stout, anteroventrally directed spiniform macrosetae.

Pedipalps: Cuticle punctate with cristulae. Coxa, retrolateral surface rugose; ventral surface smooth and punctate; coxal apophysis with one terminal spine; prodorsal surface with long, retroventrally directed macrosetae inserted in cristulae, forming stridulatory surface (pars stridens) (fig. 6G). Trochanter wider than long; retrodorsal surface punctate with short sclerotized cristulae (♂), punctate; prodorsal margin with five terminal spines (S1–S5) and one subterminal accessory spine (AS), all sharply pointed, except for S5 which is blunt (fig. 8C), varying in size such that S3 > S5 ≥ S4 ≥ S2 > S1 > AS (♂; fig. 8C) or S4 > S5 > S3 ≥ S2 > S1 ≥ AS (♀; fig. 8D); space between S3 and S4 equal to or greater than length of longest spine (♂) or subequal to space between S4 and S5 (♀); prolateral surface with several spiniform tubercles and reddish macrosetae (♂); proventral margin with two spines (♂). Femur laterally compressed (♂) or terete (♀), 2× (♀) to 2.3× (♂) longer than wide (table 4); prolateral surface with two spines, one prodorsal, short, sharply pointed, the other proventral, blunt, length one-fifth femur width (♂; fig. 9G) or short, sharply pointed, and situated apically (♀); retrolateral surface punctate, with short, distinct cristulae. Patella slightly shorter (♂) or longer (♀) than tibia (table 4); prolateral surface with few reddish macrosetae, one vestigial (♂) or distinct, sharp (♀) spine situated distally on proventral margin; one vestigial (♂) or distinct, sharp (♀) spine at base of patellar apophysis; retrolateral surface punctate with short cristulae. Patellar apophysis elongated, almost one-fifth carapace length, smooth and slender (♂) or shorter and robust (♀); prolateral margin with row of blunt (♂) or sharply pointed (♀) denticles; retrolateral margin smooth (♂) or with two denticles (♀), with subterminal macrosetae. Tibia longer than wide, laterally compressed (♂) or terete (♀); prodorsal surface with few short denticles (♂) or longer, more pronounced row of denticles (♀); prolateral surface with several reddish macrosetae; proventral margin with two spines distally; fixed finger, dorsal and ventral margins each with row of denticles. Basitarsus (movable finger), dorsal and ventral margins each with serrate row of denticles; prolateral surface with several reddish macrosetae; apex bifid (♂).

Legs: Leg I, basitarsal and telotarsal tarsomeres I–VII gradually decreasing in length, with tarsomere I longest, tarsomere VIII two-thirds length of tarsomere I. Legs I–III coxae, lateral surfaces and IV, dorsal surface each with setose spiniform tubercles. Legs II–IV trochanters, dorsal and lateral surfaces with setose spiniform tubercles; femora dorsal surfaces with setose spiniform tubercles proximally, prolateral surfaces with setose spiniform tubercles, retrolateral surfaces smooth, retroventral surfaces each with setose spiniform tubercle terminally, with macroseta inserted terminally; tibiae each with one ventrodistal spur; basitarsi each with two ventrodistal spurs. Leg I tibia with two trichobothria distally; legs II–IV tibiae each with one trichobothrium distally.

Opisthosoma: Tergites finely granular, with row of coarse granules along posterior margins; I with median longitudinal suture restricted to anterior and posterior margins; II with median longitudinal suture extending from midsegment to posterior margin; III divided by median longitudinal suture; IV with median longitudinal suture extending from anterior margin to one-third length of segment; X (first segment of pygidium) with distinct lateral longitudinal sutures (pleuron); XII with pair of oval ommatoids posterolaterally. Sternite II (genital) with semicircular depression medially (♂), pair of oblong (♂) or lanceolate (♀) depressions submedially, posterolateral surfaces inflated (♂) or flat (♀), and posterior margin protruding markedly (♂) or slightly (♀) into median lobe which overlaps sclerotized area in space between sternites II and III (♀); III divided longitudinally (♂) or undivided (♀), linear (♂) or with pronounced emargination (♀) anteriorly, posterior margin with (♂) or without (♀) median bulge with patch of reddish macrosetae (♂); IV divided longitudinally (♂) or undivided (♀); V with (♂) or without (♀) patch of fine macrosetae medially; VI–IX surfaces smooth, asetose. Spermathecae seminal receptacles triangular, posteriorly directed (fig. 12C, D); spermathecal neck short, narrow; aperture of uterus rounded, with medial notch; dorsal atrium pentagonal in dorsal aspect.

Sexual dimorphism: Adult males present several characters that differ from the females and immature stages. The pedipalps of the male are relatively elongated (fig. 9G), unlike the pedipalps of the female, which are shorter and more robust. A wide gap is present between spines S3 and S4 on the prodorsal margin of the pedipalp trochanter in the male, whereas S3 and S4 are evenly spaced in the female (fig. 8C, D). The retrolateral surface of the pedipalp femur is deeply punctate, with cristulae in the male (fig. 9G) but shallowly punctate, with weak cristulae, in the female. The patellar apophysis of the male is more slender and elongated than that of the female. The posterolateral surfaces of sternite II are slightly inflated, and a semicircular depression is present medially in the male, whereas the surfaces of sternite II are flat in the female. Sternite III is not emarginate anteriorly and exhibits a posteromedian bulge with a patch of macrosetae in the male, whereas it is emarginate anteriorly, its posteromedian margin does not protrade, and a patch of macrosetae is absent in the female (fig. 18B, D).

Additional Material Examined: MEXICO: Sonora: Municipio Cananea: Rincón del Burro, 31°02′17.448″N 110°02′11.436″W, 1566 m, 26.viii.2014, D. Barrales, gallery forest, 2 juv. (CNAN [Ur135]). U.S.A.: Arizona: Cochise Co.: Portal [31°53′02.62″N 109°12′21.13″W], 3.ix.1965, J. Jensen, 1 ♂, 1 ♀, 1 subad. ♀ (AMNH), vii.1968, W.J. Gertsch, 1 ♂, 1 ♀ (AMNH), 30.viii.1969, W.L., 1 ♂ (AMNH), B. Tomberlin, Hatari Invertebrates, 3 ♂, 1 juv. (AMNH); Portal, Southwestern Research Station, 5 mi. W Portal, 5400 ft [31°53′02.31″N 109°12′21.79″W], xi.1962, V. Roth, 1 ♂ (AMNH), 16.viii.1985, T.W. Davies, 1 ♂ (CAS); S Pedro River on road from Tombstone to Ft. Huachuca [31°36′06.80″N 110°19′44.87″W], 7.vi.1952, A. Emerson, under bark of cottonwood, 1 ♂ (AMNH). Santa Cruz Co.: Elgin, 5000 ft [31°40′26.11″N 110°35′26.38″W], 23.vii.1970, K. Galvis, 1 ♀, 1 juv. (CAS).

Distribution: Mastigoproctus tohono is recorded from northeastern Sonora, Mexico, and southern Arizona (fig. 2).

Natural History: This species inhabits the pastureland of Cananea, at an elevation of 1400–1600 m, with temperatures ranging from -2.4° to 42° C and mean annual precipitation of 545 mm. Specimens were collected under wood planks. Apparently, juveniles and adults excavate deep burrows in Arizona (J. Schmidt, personal commun.). They aestivate and hibernate in these burrows or under large boulders, emerging on the surface after the first rains. Along Cave Creek on the drive to the Southwestern Research Station, near Portal, specimens were fairly abundant after summer rains in the 1970s (O.F.F., personal obs.). Much research on vinegaroon biology was conducted with specimens of this new species (published under the name, M. giganteus). Eisner et al. (1961) studied the secretions of the abdominal glands of specimens collected at the Southwestern Research Station. Ahearn (1970) studied water relations and water loss using specimens from the Cave Creek area. Schmidt et al. (2000) studied the chemical composition of the pygidial gland secretions on specimens from Wilcox, Arizona.

Type Material: MEXICO: Sonora: Municipio Yecora: holotype ♂ (CNAN T1146), paratype ♂, paratype ♀ (CNAN T1147), paratype ♂, paratype ♀ (AMNH), paratype ♂ (CAS), Yecora, Puerto La Cruz road to Mesa del Campanero, 28°21′58.788″N 109°01′48.709″W, 2009 m, 19. viii.2016, D. Barrales and T. Lasso, mixed pine/ oak forest; paratype ♂ (CNAN T1148), Yecora, Cabañas El Campanero, 28°22′14.53″N 109°01′42.28″W, 2018 m, 30.x.2014, G. Contreras and J. Mendoza, under rock; 2 ♂ paratypes (CAS), [Moctezuma], near 28.55°N 109.45°W, 18.ix.1982, V. Roth, pine forest.

Etymology: This species is dedicated to Thomas van Devender, an ecologist and naturalist who has worked for many years on the flora and fauna of the state of Sonora and the southern part of the United States. Van Devender's contributions have helped biologists obtain a better understanding of the biota of northern Mexico.

Diagnosis: Mastigoproctus vandevenderi, sp. nov., resembles M. mexicanus, from which it differs as follows. Adult M. vandevenderi are sparsely setose and brownish in color whereas adult M. mexicanus are densely setose and reddish. Spines S3 and S4 on the prodorsal margin of the pedipalp trochanter of the adult male are equal in M. vandevenderi whereas spine S3 is longer than the other spines in M. mexicanus. The tubercles on the retrolateral surface of the pedipalp femur are curved and cup shaped in M. vandevenderi but straight and digitiform in M. mexicanus. The seminal receptacles of the spermathecae are narrow, triangular, and posteriorly directed in M. vandevenderi but swollen, obovate and anteriorly directed in M. mexicanus.

Description: The following description is based on seven males and two females.

Total length: Maximum length from anterior margin of carapace to posterior margin of opisthosomal segment XII (pygidium) in adult specimens 59.7 mm (♂) and 45.1 mm (♀) (table 5).

Color. Carapace, dark reddish brown. Tergites I–IX dark reddish brown. Sternites I–III reddish brown, lateral margins dark reddish brown; IV–IX dark reddish brown, lateral margins dark brown. Pygidium, dorsal and ventral surfaces dark reddish brown. Flagellum reddish brown, segments with reddish macrosetae. Pedipalp trochanter, dorsal and ventral surfaces dark reddish brown, prolateral surface with reddish macrosetae; femur, patella, tibia, and basitarsus, dorsal and ventral surfaces dark reddish brown, mesal surfaces with reddish macrosetae. Leg I, coxa, trochanter and basitarsus reddish brown; femur, patella, and tibia dark reddish brown; II–IV coxae, ventral surfaces light reddish brown; trochanter, femora, patellae, and tibiae, dorsal surfaces reddish brown, ventral surfaces dark reddish brown; basitarsi and tarsi reddish brown.

Carapace: Epistoma visible in dorsal aspect. Pair of strongly developed carinae anterolaterally, extending from lateral ocelli to two-thirds the distance to median ocular tubercle (fig. 10D). Three pairs of lateral ocelli with accessory translucent eyespot situated between anterior and posterior ocelli; anterior ocelli larger than median and posterior ocelli; anterior two pairs slightly separated from posterior pair by tubercle, distance between median and posterior ocelli 4× distance between anterior and median ocelli. Median ocular tubercle smooth, situated in anterior 10% of carapace (table 5); distance between ocelli 1.5× ocular diameter. Carapace anterior and medial surfaces rugose, mediolateral and posterior surfaces densely granular. Posterior fovea present, distinct.

Chelicerae: Retrolateral surface with stridulatory surface (plectrum), comprising approximately 13 short, stout (ca. 5× longer than wide), anteroventrally directed spiniform macrosetae (figs. 4H, 5H); mesal surface with few short, stout, anteroventrally directed spiniform macrosetae.

Pedipalps: Cuticle tuberculate and punctate. Coxa, retrolateral and ventral surfaces rugose; coxal apophysis with one terminal spine; prodorsal surface with long, retroventrally directed macrosetae inserted in cristulae, forming stridulatory surface (pars stridens) (fig. 6H). Trochanter longer than wide (♂) or subequal (♀); retrodorsal surface with cristulae (♂) or punctate (♀), and setose; prodorsal margin with five terminal spines (S1–S5) and one subterminal accessory spine (AS), all sharply pointed, except for AS which is blunt (fig. 8E), varying in size such that S3 ≥ S4 > S5 > S2 > S1 > AS (♂; fig. 8E) or S4 > S5 ≥ S3 > S2 > AS ≥ S1 (♀; fig. 8F); space between S3 and S4 equal to or longer than length of longest spine (♂) or equal to space between S4 and S5 (♀); prolateral surface with several spiniform tubercles and reddish macrosetae (♂); proventral margin with two spines (♂). Femur laterally compressed (♂) or terete (♀), almost 2× (♀) to 2.5× (♂) longer than wide (table 5); prolateral surface with two spines, one prodorsal, short, blunt (♂) or sharply pointed (♀), the other proventral, blunt, rounded, length one-eighth femur width (♂; fig. 9H) or short, sharply pointed, and situated apically (♀); retrolateral surface with digitiform tubercles (longer in ♂). Patella slightly shorter (♀) or longer (♀) than tibia (table 5); prolateral surface with reddish macrosetae, one vestigial (♂) or distinct, sharp (♀) spine situated distally on proventral margin; one vestigial (♂) or distinct, sharp (♀) spine at base of patellar apophysis; retrolateral surface tuberculate (tubercles larger and more numerous in ♂). Patellar apophysis elongated, almost one-quarter carapace length, smooth and slender (♂) or shorter and robust (♀); prolateral margin with row of blunt (♂) or sharply pointed (♀) denticles; retrolateral margin smooth (♂) or with few denticles (♀), with subterminal macrosetae. Tibia longer than wide, laterally compressed (♂) or terete (♀); prodorsal surface with row of denticles; prolateral surface with several reddish macrosetae; proventral margin with two spines distally; retrolateral surface with few shorter macrosetae; fixed finger, dorsal and ventral margins each with row of denticles. Basitarsus (movable finger), dorsal and ventral margins each with serrate row of denticles; prolateral surface with several reddish macrosetae; apex bifid (♂).

Legs: Leg I, basitarsal and telotarsal tarsomeres I–VII gradually decreasing in length, with tarsomere I longest, tarsomere VIII four-fifths length of tarsomere I. Legs I–III coxae, lateral surfaces and IV, dorsal and lateral surfaces each with setose spiniform tubercles. Legs I–IV trochanters, dorsal and lateral surfaces with setose spiniform tubercles; femora dorsal and ventral surfaces with setose spiniform tubercles, situated proximally on I, II, prolateral surface with setose spiniform tubercles, III and IV retrolateral surface smooth, prolateral and retrolateral surfaces smooth; II–IV retroventral surfaces each with setose spiniform tubercle terminally, with macroseta inserted terminally; tibiae each with one ventrodistal spur; basitarsi each with two ventrodistal spurs. Leg I tibia with two trichobothria distally; legs II–IV tibiae each with one trichobothrium distally.

Opisthosoma: Tergites finely granular; I divided by weak median longitudinal suture restricted to anterior and posterior margins; II with median longitudinal suture extending from midsegment to posterior margin; III with median longitudinal suture extending from anterior margin to one-third length of segment; X (first segment of pygidium) with distinct lateral longitudinal sutures (pleuron); XII with pair of oval ommatoids posterolaterally. Sternite II (genital) with pair of cup shaped (♂) or lanceolate (♀) depressions submedially, posterolateral surfaces inflated (♂) or flat (♀), and posteromedian margin protruding markedly (♂) or slightly (♀) posteriorly into median lobe that overlaps sclerotized area in space between sternites II and III (♀); III divided longitudinally (♂) or undivided (♀), linear (♂) or with pronounced emargination (♀) anteriorly, posterior margin with (♂) or without (♀) median bulge with patch of reddish macrosetae (♂); IV with (♂) or without (♀) median longitudinal suture extending from anterior margin to one-third length of segment; V with (♂) or without (♀) patch of fine macrosetae medially; VI–IX surfaces smooth, asetose. Spermathecae seminal receptacles triangular, posteriorly directed (fig. 12E, F); spermathecal neck short, narrow, markedly constricted; aperture of uterus rounded, with medial notch; dorsal atrium pentagonal in dorsal aspect.

Sexual dimorphism: Adult males present several characters that differ from the females and immature stages. The pedipalps of the male are relatively elongated (fig. 9H), unlike the pedipalps of the female, which are shorter and more robust. A wide gap is present between spines S3 and S4 on the prodorsal margin of the pedipalp trochanter in the male, whereas S3 and S4 are evenly spaced in the female (fig. 8E, F). The tubercles on the retrolateral surface of the pedipalp femur are longer in the male than the female. The patellar apophysis of the male is more slender and elongated than that of the female. The posterolateral surfaces of sternite II are slightly inflated in the male, but flat in the female. Sternite III is not emarginate anteriorly and exhibits a posteromedian bulge with a patch of macrosetae in the male, whereas it is emarginate anteriorly, its posteromedian margin does not protrude, and a patch of macrosetae is absent in the female (fig. 19B, D). Sternite V exhibits a smooth patch of setae medially in the male, which is absent in the female.

Additional Material Examined: MEXICO: Chihuahua: Municipio Temósachic: Ocampo, highway Yecora to Basaseachi, 28°27′19.5″N 108°25′49.7″W, 1922 m, P. Berea Núñez, pine/oak forest, 1 ♀ (CNAN [Ur65]). Sonora: Municipio Yecora: Microondas Yecora, 28°22′24.5″N 109°02′03.9″W, 2200 m. 13.ix.1998, M. Balcazar L., 1 ♂ (CNAN [Ur11]); [Moctezuma], near 28.55°N 109.45°W, 18.ix.1982, V. Roth, pine forest, 3 juv. (CAS); Puerto La Cruz road to Mesa del Campanero, 28°21′58.788″N 109°01′48.709″W, 2009 m, 19.viii.2016, D. Barrales and T. Lasso, pine/oak forest, 9 juv. (CNAN [Ur179]); Yecora, N of Mesa del Campanero, Rancho La Palma, 28.371°N 109.065°W, 1499 m, 4.viii.2012, T.R. van Devender and R.A. Villa, 2 juv. (CNAN [Ur114]); Yecora, Puerto La Cruz, 28°21′57.8″N 109°01′48.592″W, 1925 m, 15. viii.2015, D. Barrales, 1 ♀, 1 juv. (CNAN [Ur148]).

Distribution: Known from pine and pine/ oak forests of the Sierra Madre Occidental in eastern Sonora and western Chihuahua, Mexico (fig. 2).

Natural History: Mastigoproctus vandevenderi, sp. nov., inhabits subhumid temperate pine/ oak forest, at elevations between 1500 and 2000 m, with temperatures ranging from -14.5° to 38.5° C and mean annual precipitation of 1023 mm (fig. 1H). The largest adult series of this species was collected in the month of August, under large rocks and rotten logs. Juveniles of about the same size were observed sharing a refuge, presumably siblings that had not yet dispersed from the maternal nest. There was a notable absence of other arthropods under rocks within the area where the specimens were collected, perhaps reflecting the predatory behavior of this species. Adult males were aggressive when collected, attacking the forceps with the pedipalps. Males and females reacted similarly, spraying a strongly aromatic secretion.