LITERATURE CITED

BEARD, J. S.

1953. The savanna vegetation of northern tropical America.

Ecol. Mono., vol. 23 (2):149-215.

BOULENGER, G. A.

1898. Fourth report on additions to the batrachian collection in the Natural History Museum. Proc. Zool. Soc.

London, 1898, pp. 473-482, pls. 38-39.

BURT, C. E.

1931. A study of the teiid lizards of the genus _Cnemidophorus_ with special reference to their phylogenetic relationships. Bull. U. S. Nat. Mus., No. 154, pp. viii + 286.

CONTRERAS A., A.

1942. Mapa de las provincias climatologias de la Republica Mexicana. Mexico, D. F., Direccion de Geografia, Meterologia e Hidrologia, pp. i-xxviii, tables 1-54, 2 maps.

COOKE, C. W.

1945. Geology of Florida. Florida Geol. Surv., Geol. Bull., No. 29:1-339.

DORF, E.

1959. Climatic changes of the past and present. Contrib.

Mus. Paleo. Univ. Michigan, vol. 13 (8):181-210.

DUELLMAN, W. E.

1956. The frogs of the hylid genus _Phrynohyas_ Fitzinger, 1843. Miscl. Publ. Mus. Zool. Univ. Michigan, No. 96:1-47, pls. 1-6.

1958a. A monographic study of the colubrid snake genus _Leptodeira_. Bull. Amer. Mus. Nat. Hist., vol. 114:1-152, pls. 1-31.

1958b. A preliminary a.n.a.lysis of the herpetofauna of Colima, Mexico. Occas. Papers Mus. Zool. Univ. Michigan, No.

589:1-22.

1958c. A review of the frogs of the genus _Syrrhophus_ in western Mexico. Occas. Papers Mus. Zool. Univ. Michigan, No.

594:1-15, pls. 1-3.

DUELLMAN, W. E., and SCHWARTZ, A.

1958. Amphibians and reptiles of southern Florida. Bull.

Florida State Mus., vol. 3 (5):181-324.

DUNN, E. R.

1942. The American caecilians. Bull. Mus. Comp. Zool., vol.

91 (6):439-540.

DURHAM, J. W., ARELLANO, A. R. V., and PECK, JR., J. H.

1952. No Cenozoic Tehuantepec seaways. Bull. Geol. Soc.

Amer., vol. 63:1245.

FIRSCHEIN, I. L.

1950. A new toad from Mexico with a redefinition of the _cristatus_ group. Copeia, 1950 (2):81-87, pl. 1.

1954. Definition of some little-understood members of the leptodactylid genus _Syrrhophus_, with a description of a new species. Copeia, 1954 (1):48-58.

FIRSCHEIN, I. L., and SMITH, H. M.

1957. A high-crested race of toad (_Bufo valliceps_) and other noteworthy reptiles and amphibians from southern Mexico. Herpetologica, vol. 13 (3):219-222.

FUGLER, C. M., and WEBB, R. G.

1957. Some noteworthy reptiles and amphibians from the states of Oaxaca and Veracruz. Herpetologica, vol. 13 (2):103-108.

GLOYD, H. K.

1940. The rattlesnakes, genera _Sistrurus_ and _Crotalus_.

Chicago Acad. Sci. Special Publ., No. 4, vii + 266 pp., pls.

1-31.

GOIN, C. J.

1958. Comments upon the origin of the herpetofauna of Florida. Quart. Jour. Florida Acad. Sci., vol. 21 (1):61-70.

GOLDMAN, E. A.

1951. Biological investigations in Mexico. Smithsonian Misc.

Publ., vol. 115, xiii + 476 pp., pls. 1-71.

GOODNIGHT, C. J., and GOODNIGHT, M. L.

1956. Some observations in a tropical rain forest in Chiapas, Mexico. Ecology, vol. 37 (1):139-150.

GRISCOM, L.

1932. The distribution of bird-life in Guatemala. Bull.

Amer. Mus. Nat. Hist., vol. 64:1-439.

1950. Distribution and origin of the birds of Mexico. Bull.

Mus. Comp. Zool., vol. 103:341-382.