searchable PDF - Association for Mexican Cave Studies

only apparent troglophile is the psocid Psyllipsocusramburii Selys-Longchamps.La Libertad, San Luis Potosi.-This is an area ofdesert located west of Ciudad del Maiz at an elevationof about 1,000 meters. The four caves investigatedare all shallow, dry sinkholes formed in Jurassicgypsum. No troglobites are known from this regionand only 12 species have been identified. Of these,four are presumed troglophiles: the diplurid spiderEuagrus sp., the pholcid spider Physocyclus reddelliGertsch, the carabid beetle Agonum sp., and thestaphylinid beetle Stilicolina n. sp. The fauna istypical of that of the drier areas of northern Mexico.Matehuala, San Luis Potosi.-This region consistsof an area of karst developed on ] urassic gypsum.Most of the drainage is internal, with runoff enteringthrough shallow gypsum sinks. The two caves investigatedin the region, Sumidero de Matehuala at anelevation of 1,500 meters and Sumidero 552 at anelevation of 1,330 meters, are both small.Eight species have been determined from thisregion, none of which is troglobitic. The troglophilefauna includes the pholcid spider Physocyclus merusGertsch, carabid beetles of the genus Rhadine, andptilodactylid beetles of the genus Ptilodactyla. Thefauna resembles that of other arid regions to the westof the Sierra Madre Oriental.Micos, San Luis Potosi.-This region is locatednear the town of Micos in a series of north-southtrending ranges. The seven caves that have beenvisited are located at the base of the range at an elevationof about 250 meters. Several of these caves receivefloodwater. Mitchell et al. (1977) discuss thegeneral geology and physiography of the region andinclude descriptions of some of the caves.The 30 species known from this region include sixaquatic troglobites: the entocytherid ostracod Sphaeromicolacoahuiltecae Hobbs and Hobbs, the cirolanidisopod Mexilana saluposi Bowman, the stenasellidisopods Mexistenasellus parzeJalii Magniezand M. wilkensi Magniez, the anthurid isopod Cyathuran. sp., and the blind characin Astyanax jordani(Hubbs and Innes). The aquatic fauna is quite differentfrom that of other parts of the general region.With the exception of A. jordani all of these speciesare endemic to this region. Terrestrial troglophiles, onthe other hand, are typical of the Sierra Madre Oriental.Included are ctenid spiders of the genus Ctenus,the nesticid spiders Eidmannella pallida (Emerton)and Gaucelmus augustinus Keyserling, the scytodidspider Loxosceles valdosa Gertsch, the opilionidKaros parous Goodnight and Goodnight, the pyrgodesmidmilliped Myrmecodesmus monasticus (Causey),the gryllid cricket Paracophus placoltotus Hubbell,alleculid heetles of the genus Lystronychus, andstaphy-linid heetles of the genus Homae0 tarsus.Piedra Paloma, San Luis Potosi.-This is a limitedarea of gypsum karst located east of Ciudad del Maiz.The most notable cave known from the region isSumidero de Piedra Paloma, a largely vertical caveinto which much floodwater runs. The only troglophileknown from the region is the theridiid spiderAchaearanea porteri Banks.Puente de Dios, San Luis Potosi.-This is a poorlydefined region located southwest of Ciudad Valles.The Puente de Dios is a cave passage through whichthe Rio Santa Maria runs for a short distance. Theonly cave investigated in the region is a small onelocated along the hanks of the river.1\0 troglohites are known from this region; troglophilesinclude the pholcid spiders Modisimus bonetiGertsch and Physocyclus sp., the scytodid spiderLoxosceles sp., the rhachodesmid milliped Strongylodesmussp., the gryllid cricket Paracophus placonotusHubbell, and the leiodid beetle Ptomaphagus (Adelops)elabra Peck.Rayon, San Luis Potosi.-This ill-defined region islocated near the town of Rayon on the highway fromCiudad Valles to San Luis Potosi. The only cave thathas been studied is a small horizontal resurgenceknown as Cueva del Agua.Ten species, none troglohitic, have been identifiedfrom the cave. These include several troglophiles, alltypical of the Sierra Madre Oriental. The crayfishProcambarus (Ortmannicus) villalobosi Hohhs isknown only from here and from one cave in the SanNicolas de los Montes region. Terrestrial troglophilesinclude spiders of the genera Ctenus and Maymena,the gryllid cricket Paracophus placonotus Huhhell,the leiodid beetles Dissochaetus aztecus Szymczakowskiand D. hetschkoi Reitter, and staphylinidbeetles of the genus Belonuchus.San Nicolas de los Montes, San Luis Potosi.-Thisregion is located northwest of Ciudad Valles near thetown of San Nicolas de los Montes. Elevations rangefrom ahout 600 to 1,700 meters, with most of theknown caves lying at about 900 meters. Although afew arroyos drain part of the region, most drainage isinternal. The water level is generally shallow andseveral small lakes occur, the most notahle of whichis Laguna Grande. Karst development is characterizedhy numerous small sinkholes and shallow depressions.All of the 16 caves studied are small pits or shallowhorizontal caves; many contain water.The aquatic fauna includes three troglobites: theentocytherid ostracod Sphaeromicola cirolanae Riojaand the cirolanid isopods Speocirolana n. sp. and S.pelaezi (Bolivar). The only terrestrial troglohite is an33