EMYDID&. 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 Emys wyomingensis. It 1s 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 £. wyomingensts. 
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 
Fics. 411-413.—Echmatemys stevensontana. Carapace and plastron. 
No. 6084 A. M.N. H. 
41. Carapace. XX}. 412. Plastron. X}4. 
413. Upper surface of free border of hinder lobe of plastron. X34. 
that the edge does not extend out as far as it naturally did. The edge of his drawing ought to 
extend out about 14 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 only 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, 
