LITERATURE CITED
Carr, A.
1952. Handbook of turtles: the turtles of the United States, Canada, and Baja California. Cornell Univ. Press, xv+542 pp., 82 pls., 37 figs., 15 tables, 23 maps.
Gilmore, R. M.
1947. Report on a collection of mammalian bones from archeologic cave-sites in Coahuila, Mexico. Journ. Mammalogy, 28(2):147-165, 1 pl., 2 figs., 1 table.
Günther, A.
1885. Biologia Centrali-Americana. Reptilia and Batrachia. Chelonia, pp. 1-18.
Hamilton, R. D.
1947. The range of Pseudemys scripta gaigeae. Copeia, 1947(1):65-66.
Hartweg, N.
1939. A new American Pseudemys. Occas. Papers Mus. Zool. Univ. Michigan, no. 397, 4 pp.
Legler, J. M.
1960. Natural history of the ornate box turtle, Terrapene ornata ornata Agassiz. Univ. Kansas Publ., Mus. Nat. Hist., 11(10):527-669, pls. 15-30, 29 figs.
Schmidt, K. P., and Owens, D. W.
1944. Amphibians and reptiles of northern Coahuila, Mexico. Zool. Ser., Field Mus. Nat. Hist., 29(6):97-115.
Shannon, F. A., and Smith, H. M.
1949. Herpetological results of the University of Illinois field expedition, spring 1949. I. Introduction, Testudines, Serpentes. Trans. Kansas Acad. Sci., 52(4):494-509.
Webb, R. G., and Legler, J. M.
1960. A new softshell turtle (genus Trionyx) from Coahuila, Mexico. Univ. Kansas Sci. Bull., 40(2):21-30, 2 pls., April 20.
Williams, E.
1956. Pseudemys scripta callirostris from Venezuela with a general survey of the scripta series. Bull. Mus. Comp. Zool., 115(5):145-160, Pls. I-III, 4 figs.
Department of Zoology and Entomology, University of Utah, Salt Lake City, Utah, Transmitted May 23 1960.