226 PROCEEDINGS OF THE ACADEMY OF [1892. 



A CONTRIBUTION TO A KNOWLEDGE OF THE FAUNA OF THE 

 BLANCO BEDS OF TEXAS. 



BY EDW. D. COPE. 



Prof. E. T. Dumble, State Geologist of Texas, appointed Prof. 

 W. F. Cummins to conduct the survey of the northwestern district 

 of the state, and in pursuance of this order the latter gentleman is 

 now examining the mesozoic and cenozoic beds which compose and 

 underlie the Staked Plains. I accompanied this party in the capacity 

 of paleontologist, having already determined the vertebrate fossils 

 collected by the Survey's expeditions of last year (see Proceedings 

 of the American Philosophical Society, first No. for 1892). 



The superficial formation of the Staked Plains has been deter- 

 mined by Prof R. T. Hill to be of late cenozoic age, and the term 

 Blanco beds has been applied to it b}' Prof Cummins. The exami- 

 nation of the vertebrate fossils from it led me to state (loc. cit.) that 

 in age the Blanco formation intervenes between the Loup Fork 

 below and the Equus bed above, in the series. This conclusion was 

 based chiefly on the fact of the presence of horses of the genus 

 Equus {E. simplicidens Cope) in association with mastodons of the 

 molar dental type of the Tetrabelodon angustidens, an association 

 not previously met with in North America. In addition to these 

 species, the presence of a jDeculiar land tortoise {Testudo turgida 

 Cope), and of a new genus of birds allied to the rails (Crecoides 

 Shuf.) was established. 



I propose to present- to the Academy, a list of the species obtained, 

 so far, from the Blanco beds by the present expedition, with such 

 conclusions as may be derived from it. 



TESTUDINATA. 



Testudo turgida Cope, loc. cit. 

 Testudo pertenuis, sp. nov. 



Founded on a large specimen measuring three and a half feet in 

 length by three in width, and remarkable for the transverse width 

 of the vertebral dermal scuta. The carapace is rather flat and 

 descends steeply posteriorly, the anal marginal bone being some- 

 what incurved. Margins of carapace flare outwards above the legs. 

 The plastron has a rather wide lip, with flat base, and straight lat- 

 eral borders ; its anterior border is lost. The posterior lobe is deeply 



