THE AMPHIBIA OF OKLAHOMA 



In one prairie region of Beckham County, however, a large collection 

 of spadefoot tadpoles at and near metamorphosis contained a few individuals 

 of hammondii and also a few with jaws intermediate in character between 

 those of bombijrons and hammondii. Over 95 per cent of several hundred 

 identified were of bombijrons. It is thought probable that the intermediates 

 represent hybrids. Hybridization between these closely related species might 

 be expected in this region since it is near the eastern limits of the range of 

 hammondii. Presumably, therefore, in the breeding congress only a rela- 

 tively few hammondii mixed with many bombijrons tended to break down 

 the normal sexual isolation of the two. 



It is of further interest to note that this same site yielded almost exactly 

 the same proportions of tadpoles of the two species and of intermediates in 

 each of the two years. 



Literature Cited 



Bragg, Arthur N. 1943. Observations on the ecology and natural history of Anura. XV. 



The hylids and microhylids in Oklahoma. Great Basin Nat. 4: 62-80. 

 Bragg, Arthur N. 1946. Some new county records of Salientia and a correction in the list 



from Oklahoma. Proc. Okla. Acad. Sci. 26: 16-18. 

 Bragg, Arthur N., and Charles C. Smith. 1943. Observations on the ecology and natural 



history of Anura. IV. The ecological distribution of toads in Oklahoma. Ecology 24: 



285-309. 

 Hecht, Max K., and Bessie L. Matalas. 1946. A review of middle North American toads of 



the genus Microhyla. Amer. Mus. Novit. 1315:21 pp. 

 Walker, Charles F. 1946. The Amphibians of Ohio. Part I: The frogs and toads. Ohio State 



Mus. Sci. Bui. 1(3): 1-109. 

 Wright, A. A., and A. H. Wright. 1942. Handbook of frogs and toads. 2nd Ed. xi -|- 



286 pp. Comstock Publ. Co., Ithaca, N. Y. 



44 



