Revision of genus Texoreddellia Wygodzinsky, 1973 (Hexapoda, Zygentoma, Nicoletiidae), a prominent element of the cave-adapted fauna of Texas.

While many cave-adapted organisms tend to be endemic to single locations or restricted to single karstic regions, the troglobitic silverfish insects of genus Texoreddellia can be found in scores of different cave localities that cover a range of nearly 160,000 km2. They are among the most important and common representatives of the cave-adapted fauna of Texas and Coahuila, in northern Mexico. Using morphological and mitochondrial gene sequence data, we have corroborated the presence of at least six different species within the genus and provided species identifications to populations inhabiting 153 different cave locations. Results show that species ranges are larger than previously reported and that ranges tend to greatly overlap with each other. We have also found that different species of Texoreddellia commonly inhabit the same cave in sympatry. Data supports that some species of Texoreddellia can easily disperse through the extensive network of cracks, fissures and smaller cavities near the surface and epikarst.

Life beneath the surface of the central Texan Balcones Escarpment: genus Anillinus Casey, 1918 (Coleoptera, Carabidae, Bembidiini): new species, a key to the Texas species, and notes about their way of life and evolution.

The Texas fauna of the genus Anillinus Casey, 1918 includes three previously described species (A. affabilis (Brues), 1902, A. depressus (Jeannel), 1963 and A. sinuatus (Jeannel), 1963) and four new species here described: A. acutipennis Sokolov & Reddell, sp. n. (type locality: Fort Hood area, Bell County, Texas); A. comalensis Sokolov & Kavanaugh, sp. n. (type locality: 7 miles W of New Braunfels, Comal County, Texas); A. forthoodensis Sokolov & Reddell, sp. n. (type locality: Fort Hood area, Bell County, Texas); A. wisemanensis Sokolov & Kavanaugh, sp. n. (type locality: Wiseman Sink, Hays County, Texas). A key for identification of adults of these species is provided. The fauna includes both soil- and cave-inhabiting species restricted to the Balcones Fault Zone and Lampasas Cut Plain and adjacent areas underlain by the Edwards-Trinity Aquifer. Based on morphological and distributional data, we hypothesize that four lineages of endogean Anillinus species extended their geographical ranges from a source area in the Ouachita-Ozark Mountains to the Balconian region in central Texas. There the cavernous Edwards-Trinity aquifer system provided an excellent refugium as the regional climate in the late Tertiary and early Quaternary became increasingly drier, rendering life at the surface nearly impossible for small, litter-inhabiting arthropods. Isolated within the Edwards-Trinity aquifer system, these anilline lineages subsequently differentiated, accounting for the currently known diversity. The paucity of specimens and difficulty in collecting them suggest that additional undiscovered species remain to be found in the region.