370 GEOLOGICAL SURVEY OF THE TEERITORIES. 



AlS'OSTEIEA. 

 Aiiosteira ornata. 



An extinct genus of turtles, different from any of the preceding, is 

 indicated by many fragments of shells of a small species, obtained by 

 Prof. Hayden and Dr. Carter at Cliurcli Buttes, Grizzly Buttes, and 

 other localities in the vicinity of Fort Bridger. 



The shell is moderately compressed, broad and ovoid : in outline inter- 

 mediate in form with that of the terrapeues and the sea -turtles. The fore 

 part of the carapace is deeply and widely notched ; the back part is ex- 

 I)anded and obtuse. The marginal plates are joined by a continuous 

 suture with the costal plates, as in the terrapeues. The surface of the 

 carapace is conspicuously ornamented with closely crowded tubercles, 

 which are round or in the form of short ridge*. Xo impression of horny 

 scutes is visible on the bony plates, so that in this respect, and the orna- 

 mentation of the surface, the carapace is like that of the soft-shell tur- 

 tles or Trionyces. The i)lastron is small in its relation with the upper 

 shell, as in the Snapper ; and it firmly articulates with it by bridge* 

 which are proportionately much wider thau in the latter. The back end 

 is narrow, the fore end of greater width. The nuchal plate of the cara- 

 pace is even, but the last vertebral and the pygal plates are sharply 

 carinate. The shell of Anosteira ornata was about 5 inches in length. 



Teio^'YX. 



Trionyx guttatus. 



An extinct species of soft- shelled turtle belonged to the Bridger Ter- 

 iary period. It is indicated by many fragments of shells, which have 

 ccompanied nearly every collection of fossils from Wyoming, sub- 

 mitted to my inspection. The best specim^ is the one from which the 

 species was originally described, discovered at Church Buttes during 

 Prof. Hayden's exploration of 1868. The osseous carapace, or upper 

 shell, has measured about 14 inches in length, and upward of a foot 

 in breadth. 



Fossil turtle-eggs. 



Last summer Dr. Carter sent me numerous elongated, elliptical bodies, 

 which he had discovered in various places in the vicinity of Fort Bridger. 

 These, he observed, he thought might be the fossil eggs of some animal, 

 and, in fact, I suspect them to be fossil turtle-eggs. They present two 

 sizes, each being quite uniform. They have the same form as the eggs 

 of living terrapeues, but are smaller than those of our smallest species. 



la.ceetilia. 



Saniva. 



Saniva ensidens. 



As members of the Tertiary fauna of Wyoming, there were a number ot 

 lizards related to the living Monitors and Iguana*. The remains of one 

 of these animals, consisting of portions of a skeleton imbedded in an 

 ash-colored rock, were discovered near Granger, Wyoming, duHng Prof. 

 Hayden's exploration of 1870. They indicate an animal as large as 

 the common Iguana of South America, or one as large as any now in 



