EMYDIDjE. 



317 



proximal ends of several costals and a portion of the plastron. It is not certain that the two 

 portions of the shell belonged to the same individual, but it is probable that they did. These 

 bones are figured as cited in the synonymy. With them were figured and referred to the same 

 species a left epiplastron of another individual. This bone was barely mentioned in the original 

 description. 



The type is in the U. S. National Museum. The piece of carapace bears the number 965; 

 the piece of plastron, the number 963. The original of Leidy's fig. 4 of the plate cited bears 

 the number 976. 



Later Dr. Leidy referred all these bones to his Ernys wyomingensis. It is the present 

 writer's opinion that the two forms are not identical : but the fragment of plastron represented 

 by Leidy's fig. 4 probably belongs to E. wyomingensis. 



It is to be remarkt concerning the plastron described by Leidy that the free border of the 

 anterior lobe, from the humero-pectoral sulcus forward to the gulo-humeral, is broken away, so 



411. 



412. 



Figs. 411-413.- Echmatemys stevensoniana. Carapace and plastron. 

 No. 6084 A. M. N. H. 



411. Carapace. X. 412- Plastron. Xj. 



413. Upper surface of free border of hinder lobe of plastron. Xj. 



that the edge does not extend out as far as it naturally did. The edge of his drawing ought to 

 extend out about I J mm. further than it does. Attention may be called to the form and 

 dimensions of the vertebral scutes of Leidy's type, as they are represented in his figure. 



In the American Museum of Natural History is a specimen which is referred to this species. 

 It is a nearly complete shell, lacking onlv the right epiplastron. This shell was collected in the 

 Bridger beds of southwestern Wyoming by the museum's party in the year 1893. No further 

 details are recorded regarding the locality and the level. The matrix filling the shell is a coarse 

 sand in which are inclosed nodules of a greenish clay. The catalog number is 6084. 



The total length of the carapace, in a straight line, is 355 mm.; the greatest width 240 mm.; 

 the greatest elevation 125 mm., but this in life was greater. The plastron is convex, an indica- 

 tion that the individual was a female. 



In outline the carapace (plate 48, fig. 1; text-fig. 411) is a rather narrow oval, contracted 

 in front of the fore legs. It is slightly excavated above the neck and the hinder end is rather 

 pointed. Posteriorly the peripherals flare slightly upward. The free borders of the nuchal. 



