1923. The reappearance of Batrachyla longipes. Proc. New England Zool. Club, 8:81-83. BARBOUR, T., and A. LOVERIDGE 1946. Typical reptiles and amphibians; supplement. Bull. Mus. Comp. Zool., 96:59-214. BOULENGER, G. A. 1882. Catalogue of the Batrachia Salientia ... British Museum., 2nd ed. 1888. Note on the classification of the Ranidae. Proc. Zool. Soc. London, 1888, pt. 2:204-06. CAMPBELL, H. W., and R. S. SIMMONS 1962. Notes on some reptiles and amphibians from western Mexico. Bull. So. California Acad. Sci., 61:193-203. CONANT, R. 1958. A field guide to reptiles and amphibians. Houghton-Mifflin Co. Boston. 366 pp. COPE, E. D. 1866. On the structures and distribution of the genera of the arciferous Anura. J. Acad. Nat. Sci. Philadelphia, n. ser., 6:67-112. 1877. Tenth contribution to the herpetology of tropical America. Proc. Amer. Philos. Soc., 17:85-98. 1878. New genus of Cystignathidae from Texas. Amer. Nat., 12:252-53. 1879. Eleventh contribution to the herpetology of tropical America. Proc. Amer. Philos. Soc., 18:261-77. 1885. A contribution to the herpetology of Mexico. _Ibid._, 22:379-404. DAVIS, W. B., and J. R. DIXON 1957. Notes on Mexican amphibians, with description of a new _Microbatrachylus_. Herpetologica, 13:145-47. 1965. Amphibians of the Chilpancingo Region, Mexico. _Ibid._, 20:225-33. DIAZ DE LEON, J. 1904. Indice de los Batracios que se enquentran en la Republica Mexicana. Imprenta de Ricardo Rodriquez Romo. Aguascalientes. 40 pp. DIXON, J. R. 1957. Geographic variation and distribution of the genus Tomodactylus in Mexico. Texas J. Sci., 9:379-409. DIXON, J. R., and R. G. WEBB 1966. A new _Syrrhophus_ from Mexico (Amphibia: Leptodactylidae). Cont. Sc., Los Angeles Co. Mus., 102:1-5. DUELLMAN, W. E. 1958. A review of the frogs of the genus _Syrrhophus_ in western Mexico. Occ. Pap. Mus. Zool. Univ. Michigan, 594:1-15. 1960. A distributional study of the amphibians of the Isthmus of Tehuantepec, Mexico. Univ. Kansas Publs. Mus. Nat. Hist., 13:19-72. FIRSCHEIN, I. L. 1954. Definition of some little-understood members of the leptodactylid genus _Syrrhophus_, with a description of a new species. Copeia, (1):48-58. FOUQUETTE, M. J. 1960. Call structure in frogs of the family Leptodactylidae. Texas J. Sci., 12:201-15. GADOW, H. 1905. The distribution of Mexican amphibians and reptiles. Proc. Zool. Soc. London, 1905, pt. 2:191-244. GORHAM, S. W. 1966. Liste der rezenten Amphibien und Reptilien.... Das Tierreich. Lief, 85:1-222.