CHAPTER III. 



THE VERTEBRATE FAUNA OF THE BLANCO BEDS, 



A report on collections made in these beds by Mr. W. F. Cummins 

 was made by me and published in the Third Annual Report of the Geo- 

 logical Survey of Texas, 1891, p. 251. During the past season I accom- 

 panied Mr. Cummins in a more tliorough exploration of this formation, 

 near the eastern border of the Staked Plain, and we added materially 

 to the knowledge of its vertebrate fauna. The results will be found in 

 the following pages. The inference as to the position of the Blanco ter- 

 ranes in the Cenozoic series wliich I formerly announced, are confirmed; 

 viz, , that its position is between the Loup Fork and Equus terranes. The 

 fauna is intermediate and peculiar, as not a single species occurs in it 

 which has been found in the terranes prior or subsequent to it in time. 

 The horizon is more nearly and strictly Pliocene than any of the lacus- 

 trine terranes hitherto found in the interior of this continent. 



TESTUDINATA. 

 TESTUDO, Linn. 



TESTUDO TURGIDA, Cope. 



Proceedings Amer. Philosoph. Society, 1892, p. 127; Ann. Report 

 Geol. Surv. Texas, 1891, p. 255 (published 1892). 



Seven specimens of this species were found together at one locality, 

 which did not yield any other vertebrate remains, fragments of two 

 other individuals were found at other localities in direct association with 

 Mammalia. 



TESTUDO PERTENUIS, Cope. 



Proceedings Academy Nat. Sciences, Philadelphia, 1892, p. 226. 



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 somewhat incurved. Margins of carapace 

 flare outwards above the legs. The plastron has a rather wide lip, with 

 flat base and straight lateral borders ; its anterior border is lost . The 

 posterior lobe is deeply and widely notched, terminating on each side in 

 a subequilateral angular prominence. Both carapace and plastron are 

 without sculpture, the posterior angles of the plastron only being longi- 



