MEXICAN TAILLESS AMPHIBIANS 29 



1863. Incilius Cope, Proc. Acad. Nat. Sci. Philadelphia, vol. 15, p. 50, Mar. 



[Genotype, Chilophryne conifera Cope = Bw/o coniferus Cope, 1862, Proc. 



Acad. Nat. Sci. Philadelphia, vol. 14, p. 158, Mar.] (See also Cope, 1865, 



Nat. Hist. Rev., p. 102.) 

 1865. Epidalea Cope, Nat. Hist. Rev., p. 102, Jan. [Genotype, Epidalea calamita 



CoFE = Bufo calamita Laurenti, 1768, Synopsin reptilium, pp. 27, 119 



(Europe) .] 

 1868. Otaspis Cope, Proc. Acad. Nat. Sci. Philadelphia, vol. 20, p. 312, Nov. 



[Genotype, Otaspis empusa Cove = Peltaphryne empusa Cope, 1862, Proc. 



Acad. Nat. Sci. Philadelphia, vol. 14, p. 344, Sept. (Cuba).] 

 1870. Nannophryne GtJNTHER, Proc. Zool. Soc. London, p. 402, June 9. [Geno- 

 type, Nannophryne variegata GtJNTHER, idem, p. 402, pi. 30, fig. 2 (Puerto 



Bueno, Port Grappler, and Eden Harbour, in Territorio Magallanes, west 



coast of South America).] 

 1870. Ansonia Stoliczka, Journ. Asiatic Soc. Bengal, vol. 39, pt. 2 (Nat. Hist.), 



p. 152, June 7. [Genotype, Ansonia penangensis Stoliczka, idem, p. 152, 



pi. 9, fig. 4 (Penang Island, Straits Settlements).] 

 1876. Cranopsis Cope, Journ. Acad. Nat. Sci. Philadelphia, ser. 2, vol. 8, pt. 2, 



p. 96. [Genotype, Cranopsis fastidiosus Cope, idem, p. 96, pi. 23, figs. 1, 



la (2,500 feet elevation on slope of Pico Blanco, district of Uren, Costa Rica) .] 

 1876. Crepidius Cope, Journ. Acad. Nat. Sci. Philadelphia, ser. 2, vol. 8, pt. 2, 



p. 97. [Genotj^pe, Crepidius epioticus Cope, idem, p. 97, pi. 23, figs. 2, 2a 



(5,000 feet elevation on Pico Blanco, Costa Rica).] 

 1876. Ollolis Cope, Journ. Acad. Nat. Sci. Philadelphia, ser. 2, vol. 8, pt. 2, 



p. 98. [Genotype, Ollotis coerulescens Cope, idem, p. 98, pi. 23, figs. 3, 3a 



(3,000 to 5,000 feet elevation on Pico Blanco, Costa Rica).] 

 1879. Dromoplectrus Camerano, Atti R. Accad. Sci. Torino, vol. 14, p. 882. 



[Genotype, Dromoplectrus anomalus Camerano = Bu/o anomalus GtJNTHER, 



1858, Catalogue of the Batrachia Salientia in the collection of the British 



Museum, p. 57 {Mexico) = Bufo compactilis Wiegmann, 1833, Isis von Oken, 



vol. 26, pt. 7, p. 661 (Mexico).] 



Tliirteen species of Bufo are recognized in Mexico. One, B. 

 alvarius, is semiaqaatic and has a rather smooth leathery skin, but 

 most of the species are mainly terrestrial except during the breeding 

 season. Three others, B. compactilis, B. cognatus, and B. woodhousii, 

 have a large shovellilie inner metatarsal tubercle, which facilitates 

 burrowing. The extent to which cranial crests are developed con- 

 stitutes an important diagnostic character for many species. Cranial 

 crests are quite prominent in some, especially in B. valliceps, which 

 has high sharp-edged bony ridges. Conversely, there are others, 

 particularly B. punctatus, that have a nearly flat interorbital region 

 and normally are devoid of such crests. Abnormal development or 

 peculiarities in the conformation of the cranial crests are occasionally 

 observed in a large series of any species of Bvfo. The Mexican toad 

 B. cristatus may be an instance of this sort, for, with the exception of 

 the peculiarly enlarged parietal crests, it conforms in most respects 

 to the valliceps type of toad. The nondevelopment of certain cranial 

 crests when associated with an exceptionally tubercular skin, such 

 as has been hereinafter described in the case of certain individuals 

 66785—32 3 



