PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON 113(3):815-819. 2000. A new species of diminutive salamander (Amphibia: Caudata: Plethodontidae: Nototritoh) from the Montaiias del Mico of Guatemala David B. Wake and Jonathan A. Campbell (DBW) Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, California 94720-3160, U.S.A.; (JAC) Department of Biology, University of Texas at Arlington, Arlington, Texas 76019-0498, U.S.A. Abstract. — Nototriton stuarti, a new species of salamander belonging to the tribe Bolitoglossini, family Plethodontidae, is described from the Montaiias del Mico, north of the Motagua Valley, in eastern Guatemala. The species is geo-graphically isolated from congeneric species, and represents the northwestern-most record for the genus, which ranges from eastern Guatemala to central Costa Rica. This poorly known species is morphologically most similar to Nototriton barbouri, which occurs in northwestern Honduras. Homoplastic evolution has produced di-minutive, attenuate salamanders in many different clades of plethodontid salaman-ders in Middle America. These tiny species are difficult taxonomically and it has taken much effort to recognize that there are many more species than have been named throughout this region. New discoveries and new data have led to taxonomic revi-sions that are gradually identifying mono-phyletic groups, and as this process goes forward the generic level taxonomy has changed repeatedly. This is especially true of the genus Chiropterotriton Taylor, 1944, which as formerly recognized ranged from northeastern Mexico to Costa Rica, but which was not monophyletic and now has been fragmented into four genera {Chirop-terotriton, Cryptotriton Garcia-Paris & Wake, 2000, Dendrotriton Wake & Elias, 1983, and Nototriton Wake & EHas, 1983). At present diminutive plethodontids found to the north and west of the Isthmus of Te-huantepec are assigned to Chiropterotriton (Darda, 1994), but, in addition, all members of the genera Parvimolge Taylor, 1944, Li-neatriton Tanner, 1950, and especially Thorius Cope, 1869, none closely related to Chiropterotriton and all endemic to this area, are also diminutive. To the south and east of the Isthmus of Tehuantepec, extend-ing as far as central Costa Rica, diminutive species are found in one well-supported clade (Garcia-Paris & Wake 2000). This clade includes the genera Cryptotriton, Dendrotriton, Nototriton and Oedipina, and possibly the poorly known Bradytriton Wake & EUas 1983 (G. Parra-Olea, pers. comm.). Oedipina Keferstein 1868 includes some diminutive species, but also some large and relatively robust, although elon-gated, species. The phylogenetic diversity of this clade is now understood, at least in broad outlines. Oedipina and Nototriton ap-pear to be the most deeply nested groups (Garcia-Paris & Wake 2000), and they are also the most southerly in distribution, ex-tending to Ecuador (moderately large spe-cies of Oedipina occur in South America, Brame & Wake 1963) and central Costa Rica, respectively. Both occur as far north as Guatemala, and Oedipina ranges into Chiapas, Mexico. Cryptotriton and Dendro-triton range from Honduras into Mexico, the former possibly even north and west of the Isthmus of Tehuantepec [the species
BioStor
