CHECKLIST OF THE SNAKES OF MEXICO 65 



name may be used, according to the choice of the first reviser, who in this 



case is the author himself). — Smith, Smithsonian Misc. Coll., vol. 90, No. 19, 



1941, pp. 1-6 (key to Mexican species). 

 Babdosoma Dumekil, M§m. Acad. Sci. Inst. France, vol. 23, 1853, p. 440 (type, R. 



semidoUatum Dum^ril and Bibron). 

 Oeophidiiim Petebs, Monatsb. Akad. Wiss. Berlin, 1861, p. 923 (type, G. duhium 



Peters). 

 Parageophis Bocouet, Mission scientiflque au Mexique et dans I'Am^rique 



centrale. Kept., livr. 9, 1883, p. 534 (type, RaMosoma semidoUatum Dum6ril, 



Bibron, and Dumeril). 

 Diroscma Botrr-ENGEK, Catalogue of snakes in the British Museum, vol. 2, 1894, 



p. 298 (type, Oeophis Hcolor Giinther). 



Genotype. — Catostoma chalyheus Wagler. 



Range. — Central Mexico (San Luis Potosi) southward on the 

 plateau and in foothills, through Central America to Brazil. 



Species. — In all, 20 occur in Mexico,^^ and about 14 others in Cen- 

 tral America and northern South America.^^ 



KEY TO MEXICAN SPECIES OF GEOPHIS 



1. An anterior temporal separating parietal from labials 2 



No anterior tempoi*al, parietal in contact with a labial 8 



2. Six supralabials 3 



Seven supralabials; about 40 irregular cross bars on body and tail. 



isthmicus 



3. Sixth labial distinctly longer than others ; ventrals 152 or less 4 



Fifth labial longest; ventrals 152 or more 5 



4. Light cross bands visible on body anteriorly ; seven lower labials. 



omiltemaua 

 No cross bands on body ; dark above, with a light spot on snout ; five 

 lower labials maculiferus 



5. Entire body and tail with numerous, dark cross bands, 37 to 43 ; caudals 



37 in two females, 40 to 49 in two males semiannulatus 



No cross bands on body, save sometimes a light nuchal collar; caudals 

 26 to 34 in females, 31 to 41 in males 6 



6. Prefrontals much longer than broad long'iceps 



Prefrontals little longer than broad 7 



7. Brown or slate above ; never a light nuchal collar ; belly light, with dark 



stippling ; ventral surface of head and neck light, unmarked ; caudals 



30 to 34 in females latifroutalis 



'"Oeophis rhodogaster (Cope) (Proc. Acad. Nat. Sci. Philadelphia, vol. 20, 1868, pp. 130- 

 131, 2 figs.) was originally described from near Guatemala City, and in spite of the refer- 

 ence of the species to the Yucatan fauna by all authors since 1887 there is no apparent 

 reason for believing the original citation incorrect. The error in referring the species to 

 Yucatan began with Cope's 1887 checklist (U. S. Nat. Mus. Bull. 32, p. 86) and has not been 

 rectified since. So far as known at present, it does not occur in Mexico, although it may 

 be found eventually in Chiapas. 



'■^ It is not certain that the three South American Oeophis {poppigi, ruthveni, diplo- 

 zeugus) are actually congeneric with northern species. The absence of the anterior tem- 

 poral distinguishes South American "Oeophis" from Atractus, which has it ; yet in Mexican 

 Bpecies of Oeophis both conditions occur. The hemipenial character (bifurcate hemipcnis in 

 Atractus, simple in Oeophis) is perhaps a more reliable generic character, yet its condition 

 is unknown in South American "Oeophis." The generic status of all the snakes of this 

 section Is in need of review. 



