Reithrodontomys megalotis and R. montanus, two species of harvest mouse that co-occur at low elevations of the southeastern Rockies and western Great Plains, are notoriously difficult to distinguish both externally and cranially, particularly for juveniles. Three external characteristics and 14 cranial measurements were used in discriminate function analyses (DFA) to detect the most robust measurements for species identification. Using 151 and 66 specimens of R. megalotis and R. montanus, respectively, from Colorado, we constructed DFA models for all specimens combined and segregated into four age classes by tooth wear. Due to substantial overlap in measurements, DFA models could not reliably predict species identity based on external or cranial characteristics alone, whereas models including all characteristics were more reliable. The most reliable DFA models were those for each age class (juvenile, subadult, adult, and old adult) using all external and cranial measurements. With various DFA models, 19 juvenile and subadult specimens of Reithrodontomys sp. from recent trapping efforts were all classified as R. megalotis with an average probability of 99.7%. Tail stripe width was also shown to be an unreliable identifier. We advocate using combined external and cranial measurements segregated by age class to robustly discriminate between these two species, particularly when identifying young individuals.

A new species of crayfish, Cambarus (Jugicambarus) magerae, is described from southwestern Virginia within the Valley and Ridge physiographic province of the North American Appalachian Mountains. The species is one of the smallest and most geographically restricted in the subgenus and possibly the genus. Morphologically, it is similar to Cambarus (J.) parvoculus Hobbs & Shoup, 1947 and Cambarus (J.) jezerinaci Thoma, 2000. It can be distinguished from both by its proportionally wider areola. Its distribution appears to be restricted to a single gorge in the South Fork Powell River upstream of Cracker Neck, a village east-southeast of Big Stone Gap located at the base of Powell Mountain.

We describe a new species of Batomys from Mt. Isarog, southern Luzon. Morphological and genetic studies of newly obtained specimens of Batomys granti from the type locality on Mt. Data and other high mountains in the Central Cordillera of northern Luzon, and previously referred specimens from Mt. Isarog on the southern peninsula of Luzon, support the separation of the population from Mt. Isarog as a distinct species that is sister to B. granti and demonstrate the existence of B. granti as a widespread species in the Cordillera. The new species occurs only in montane and mossy forest from 1350 m to 1800 m, and is separated from the nearest known population of B. granti by about 450 km. Limited ecological data indicate that it is a nocturnal herbivore. Recognition of this species raises the number of native murid species on Luzon to 44, and the number of species in the endemic Philippine cloud-rat clade to 18. The new species occurs within a national park that is not currently under threat.

A new species, Elanella haifensis, is described from off the coast of Israel, collected in depths ranging from 9.8–22.4 m. It is easily distinguishable from congeners by the spinulate bulbous setae III and IV of the female caudal ramus, and the shape of the male antennule. A new diagnosis is presented for the genus Elanella. This is the first record of the genus in Mediterranean waters.

An outbreak of the fish-ectoparasitic marine isopod Caecognathia coralliophila (Monod, 1926) occurred in a fish hatchery in Sabah on Borneo Island, Malaysia. Larval stages of gnathiid isopods are parasitic on fish whereas their adult stages are free-living. The original description of C. coralliophila (Monod, 1926) was based on the morphology of one adult male from Thailand, and no description of the adult female or larva has been published to date. We compared the holotype of C. coralliophila and redescribed adult males and adult females as well as third-stage larvae from the fish hatchery. This paper provides a redescription of C. coralliophila based on all phases of the life history. Caecognathia coralliophila is distinguished from congeners by having reduced setae on the distal margins of the pleopodal endopods in adult males, biarticulate pylopods and the setae on the pleopodal rami being reduced in adult females, and antenna much longer than antennule in third-stage larvae.

In 1817, the naturalist Constantine S. Rafinesque named nine new species of mammals from the American West, indicating the recently published journal of Charles Le Raye as the primary source for his descriptions. Le Raye was purported to be a French Canadian fur trader who, as a captive of the Sioux, had traveled across broad portions of the Missouri and Yellowstone river drainages a few years before the Lewis and Clark Expedition (1804–1806) traversed much of the same region. Le Raye's journal was relied upon by generations of scholars as a valuable source documenting the native peoples and natural history of the Upper Missouri River in the era just prior to European settlement. Subsequent research, however, has shown that Le Raye never existed, and his purported journal is fraudulent. Despite this, Rafinesque's creation of the names followed conventional and accepted practice at the time, and they are potentially available. Fortunately, much of the Le Raye journal was based on verifiable sources, such as Patrick Gass's published account of the Lewis and Clark Expedition. Identification of the original source materials makes it possible to establish the correct application of Rafinesque's names and to determine their current status. This process reveals that the earliest scientific name for the coyote (Canis latrans Say, 1822) was Canis chlorops Rafinesque, 1817; this name is now a nomen oblitum, however, and is no longer available.

A new enchytraeid species, Mesenchytraeus asymmetriauritus sp. nov., collected from terrestrial habitats of Changbai Mountain in the northeast China, is described. It is characterized by the dorsal vessel originating in XV–XVII, four pairs of preclitellar nephridia in 6/7–9/10, spermathecae attached to oesophagus in segment V and each possessing three or four ear-shaped diverticula of different size, one pair of asymmetrical sperm sacs occupying X–XVII and containing bulk of naked sperm bundles, atrium cylindrical with 4 prostate-like glands and distinct from vas deferens, and well-developed egg sac extending to XVI–XVII.

A new species, Monokalliapseudes guianae, is described from French Guianese estuaries. It is distinguishable from its only congener most notably by lacking an exopodite on pereopod 1 and by the nature of the basal article of the uropod. The inner distal corner of the basal article is only slightly produced and lacks a rounded lobe. The bases of pereopods 2 and 3 lack numerous long setae. Sexual dimorphism is observed in the antennule, cheliped, and pereopod 1. Depending on size, males can exhibit two forms of chelae. A new diagnosis is presented for the genus Monokalliapseudes.

Adult populations of Ocypode quadrata have not been reported north of Cape Cod, Massachusetts, but their megalopae, which invade sandy beach habitats, have been recovered recently from the coasts of Massachusetts and Maine. Two megalopa specimens were reported from Maine beaches at Kennebunkport and Kennebunk in 2012. More recently in September 2014, a specimen was collected from Pemaquid Beach, Bristol, Maine, ~ 96 km north of the Kennebunkport-Kennebunk region. Herein, we also report the occurrence of three specimens of first crab instars from Goose Rocks Beach, Kennebunkport, collected on October 2–3, 2014. These juvenile crabs were found slightly above the tide line of the previous high tide, where they were preserved and measured (mean carapace width x carapace length = 6.34 ± 0.38 mm x 5.64 ± 0.34 mm; mean carapace width/carapace length ratio = 1.13). This is the first evidence for megalopa to first crab metamorphosis of ghost crabs in the cold waters beyond Cape Cod. Conformation of survival of early crab instars of O. quadrata, a primarily southern latitude brachyuran, to adulthood in Gulf of Maine waters requires further collections and experimentation.

A new species of tardigrade in the family Echiniscoididae, Echiniscoides wyethi, was found on the barnacle Semibalanus balanoides (L.) at several intertidal sites around Allen Island, Maine, USA. The new species is named after the American artist Andrew Wyeth and the Wyeth family who own the island on which this species was discovered. The new species is separated from all other Echiniscoides by the smooth cuticle, long flexible buccal tube, and the number of claws on the legs of the adult.

The endemic hummingbirds Trochilus polytmus and T. scitulus hybridize in a narrow zone of secondary contact in eastern Jamaica. The cline in bill width across the hybrid zone represents the steepest morphological gradient documented thus far in avian biology. Hindlimb size and skeletal proxies for core body size, however, exhibit incongruent patterns of variation across the same transect. Significant correlation between bill width and skull width indicates that genetic loci that affect bill width have pleiotropic effects on cranial morphology posterior of the craniofacial hinge. This study is the first direct examination of skeletal size variation across an avian hybrid zone.