The Kishenehn Formation of northwest Montana and southeast British Columbia hosts one of the most prolific and diverse assemblages of fossil nonmarine mollusks in North America. More than 76 taxa, of which 41 are newly described species, of middle Eocene to early Miocene terrestrial and aquatic gastropods have been collected and described. This paper reports on the discoveries made in the oldest part of the formation that is middle Eocene in age in the southernmost part of the Kishenehn Basin. Outcrops along the Middle Fork of the Flathead River from this area have yielded over 1400 specimens from which 62 taxa (37 terrestrial, 25 aquatic) were identified. Of these, eight are new species and nine were described elsewhere but were not previously reported in the formation.

In terms of paleoenvironmental affinities, the fauna are divisible into three groups. Group I is a relict tropical wet fauna, existing in basinal waterways whose modern analogs live in the Caribbean and Central and South America. Group II is a subtropical, semi-arid fauna with modern analogs ranging from the north coast of the Gulf of Mexico, across the southern United States and northern Mexico to southern California and the Baja Peninsula. Group III is a humid, warm temperate fauna that was transported from mountains east of the basin and deposited in fan-delta and lake-margin settings. Modern analogs of these molluscan taxa are common in the east-central United States. The unusual coexistence of these climatically disparate groups of fossil mollusks is a manifestation of the large paleotopographic relief, perhaps greater than 2000 m, that existed between the valley floor and the mountains.

The following taxa are described herein by the senior author (HGP) as new species: Bivalvia: Sphaeriidae- Sphaerium lentum, Pisidium triangulatum. Gastropoda: Proserpinellidae- Tozerpina elsae; Subulinidae- Obeliscus scalplockensis; Planorbidae- Ferrissia circus, Rhodacmaea crepida, Omalodiscus spira; Physidae- Physella olive; and one new subspecies: Gastropoda: Pupillidae- Pupilla hebes sinistra.

This paper describes a new African skipper, Procampta admiratio (Lepidoptera: Hesperiidae: Pyrginae: Tagiadini), inhabiting much of the Democratic Republic of Congo. It cannot be distinguished by external features from Procampta rara Holland, 1892, from Gabon, the Central African Republic, and West Africa. For 122 years the genus Procampta Holland, 1892, was thought to be a monotypic genus. The genitalia of the two species are very different and it was possible to confirm that those of the P. rara holotype were West African. On present knowledge the two species are wholly allopatric, though a specimen from Bangui, Central African Republic, is only 220 km north of the nearest P. admiratio.

Two subgenera (nominotypical subgenus Orthopsylloides and Mirzapsylla, new subgenus) are established within the flea genus Orthopsylloides Rothschild and Jordan, 1922. Within subgenus Orthopsylloides, four new species are described: Orthopsylloides (Orthopsylloides) mardoni, O. (O.) maricaballa, O. (O.) penguinata, and O. (O.) uncinata. An additional four new species are described in the new subgenus Mirzapsylla: Orthopsylloides (Mirzapsylla) rawlinsi, O. (M.). repanda, O. (M.) truncata, and O. (M.) whitingi. Females of O. (M.) mardoni and O. (M.) rawlinsi remain unknown. Orthopsylloides (O.) orthodactylus owiensis Holland, 1969, and Orthopsylloides (O.) abacetus baiyerensis George and Beaucournu, 1995, are each synonymized with their nominate taxa. Nine additional new species of the genus Parastivalius Holland, 1969, are described: P. avicularius, P. bidenticulatus, P. chelaformis, P. longipalpus, P. novaebritainiae, P. papillatus, P. phocaceus, P. spinatus, and P. tridenticulatus. Host associations are discussed and a table of host/parasite relationships is provided. An illustrated key to the valid species of Nestivalius Traub, 1980, Orthopsylloides, and Parastivalius is included. With the addition of 17 new species and new synonymy of two subspecies, there is a total of 93 species within the superfamily Pygiopsylloidea in Papua Province (Indonesia), Papua New Guinea (PNG, including Bismarck Archipelago), and the Solomon Islands. An additional eight species belonging to three other flea families [Ischnopsyllidae (3), Pulicidae (3), and Leptopsyllidae (2)] bring the total number of valid flea taxa in the region to 101 species (including subspecies).

Twenty species of rodents are recognized from the early Whitneyan Cedar Pass Fauna of South Dakota. Two new species are recognized, the sciurid Douglassciurus bjorki (including specimens originally referred to Cedromus wilsoni Korth and Emry, 1991, from the late Whitneyan Blue Ash Fauna) and the cricetid Paciculus cedrus. Due to a more complete record at Cedar Pass, the florentiamyid Hitonkala martintau Korth, 2008, is allocated to the genus Kirkomys Wahlert, 1984 as a new combination, Kirkomys martintau (Korth, 2008). The new sample of this species also allows for a description of the complete cranium of Kirkomys previously only known from a single partial skull.

Among the genera of rodents identified from Cedar Pass, two earlier occurring genera have their last occurrence and six later occurring genera have their first occurrence. Thirteen genera that extend into the Arikareean present in the later Whitneyan Blue Ash Fauna are lacking in the Cedar Pass Fauna. Only one genus of rodent is limited to the Whitneyan, Disallomys Korth, 2009a. This demonstrates that the age represented by the fauna at Cedar Pass is transitional between the Orellan and later Whitneyan horizons. The proportions of rodents (relative number of specimens and species) also differ between the Cedar Pass and the Blue Ash faunas, again, indicating an earlier age for the Cedar Pass Fauna.