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large genus with numerous epigean species, mostknown only from the southern part of its range.Troglobitic species have been described from Chiapas,Oaxaca, Queretaro, San Luis Potosi, Tamaulipas,and Nuevo Leon. With the exception of H. boneti(Goodnight and Goodnight) from caves of the Sierrade EI Abra and Sierra de Guatemala and H. osorioi(Goodnight and Goodnight) from three isolatedmountain ranges in Nuevo Leon, all of the species arerestricted to high elevations. Two additional high.elevation relicts, both assigned by Silhav), (1974) tothe genus Troglostygnopsis, may also belong in Hoplobunus.Two troglobitic species of Hoplobunus inTexas are apparently tropical relicts in a temperateregIon.The milliped family Rhachodesmidae ranges fromCentral America into Nuevo Leon and has been amajor contributor to the troglobite and troglophilefauna of this region. Six genera of this family containtroglobites, all but one of which also containepigean species. Aceratophallus ranges north intoChiapas and Yucatan, with several troglophiles knownfrom Yucatim. The only troglobite is A. scutigeroidesShear from Alta Verapaz, Guatemala, and possiblyChiapas. Acutangulus includes five species from Veracruz,but the only troglobite is A. alius Causey fromthe Orizaba region. Two troglobitic species of Ceuthauxushave been described, one from the Cacahuamilparegion of Guerrero and the other from Grutasdel Palmito, Nuevo Leon. This genus ranges fromMorelos and Veracruz into Coahuila. The genusPararhachistes includes two epigean and one troglobiticspecies in Guerrero. Several species of Strongylodesmushave been described from Mexico, but theonly troglobite is S. harrisoni Causey from the Sierrade Guatemala This is a fairly recent troglobite andmay now be restricted to caves at higher elevations.The most important genus of rhachodesmid millipedin Mexican caves is Unculabes. This genus includesonly five species, all known only from caves in SanLuis Potosi, Queretaro, and Tamaulipas. All but oneof these are troglobitic.Mexico contains a rich truglobitic gryllid cricketfauna, with four species in two genera described.Tohila atelomma Hubbell is a species known onlyfrom caves in the Yucatan Peninsula. It is apparentlymost closely related to the genus Paracophus.The latter genus is known only from the SierraMadre Oriental, where three troglobitic and fivetroglophilic species are found. The three troglobites-Pocaecus Hubbell from the Sierra de Guatemala,P. cladonotus Hubbell from southern SanLuis Potosi and adjacent Hidalgo, and P. lippusHubbell from tlle Sierra EI Pino region of San LuisPotosi-are restricted to high elevations.The last group to warrant mention here includesspecies belonging to genera which are widespread inboili tropical and temperate regions. Among the moreimportant of these groups are spiders of the familiesDipluridae, Theraphosidae, and Pholcidae; millipedsof ilie families Cleidogonidae and Spirostreptidae;entomobryid collembolans of the genus Pseudosinella;and beetles of the family Leiodidae.The spider suborder Mygalomorphae tends to bepoorly represented in caves, but two families includetroglobites in Mexico. The Dipluridae includes twodescribed troglobites, Euagrus anops Gertsch fromthe Xilitla region and E. cavernicola Gertsch from theSierra de Guatemala; both occur only at high elevations.The family Theraphosidae is represented inMexican caves by two troglobites: Schizopelmareddelli Gertsch from caves in the Acatlan region ofOaxaca and S. stygia (Gertsch) from the Xilitla region.The first species occurs at low elevations, whilethe latter is found at higher ones.One of the most characteristic features of thecavernicole fauna of this region is the presence incaves of numerous spider species belonging to thefamilv Pholcidae. Troglobitic species are found inthe genera JUetagonia, Pholcophora, and Psilochorus.lIetaf!oniaincludes lowland troglobites in Veracruz.Oaxaca, Tamaulipas, the Yucatan Peninsula, andBelize. Highland troglobites are found in the Sierra deGuatemala and Xilitla regions. Two of the three troglobiticspecies of Pholcophora in Mexico are knownfrom lowland eavt·s in Guerrero and the YucatimPeninsula. The third species of Pholcophora and thetwo troglohitic Psilochorus species are found in thecaves of Chihuahua and Durango where they are isolatedhy the surrounding desert.The cleidogonid millipt~d genus Cleidogona is ofinterest in that the most highly cave-adapted speciesin the genus, C. crucis (Chamberlin) from the Atoyacregion of Veracruz, is found at the lowest elevation ofany of the troglobites. The remaining troglohiticspecies of the genus are found at higher elevations inthe states of Oaxaca, Chiapas, and Tamaulipas. Thegenus Cleidogona ranges from Central America intothe United States; Shear (1972) speculates that thegenus originated in the Mexican highlands.Although only two species of the spirostreptidmilliped genus Orthoporus have become troglobites,they are of particular interest in that they are theonly troglobites in the genus. The species of Orthoporustend to have very wide ranges and to be highlyvagile. Orthoporus spelaeus Causey has been found66