EMYDID^E. 



39 



humeral sulci run directly backward. The hone is thickened backward a distance of 20 mm. 

 The horn-covered band is 17 mm. wide at the hyoepiplastral suture. 



In 1870, as cited above, Dr. Leidy described his Emys jeanesi from a quite complete shell 

 found near Fort Bridger. In 1873 he referred this specimen to his earlier E. wyomingensis. 

 An examination shows that its epiplastron is as nearly like that forming the type of E. wyoming- 

 ensis as could be expected in two individuals of the same species. The width of that of E. 

 jeanesi is 54mm.; the thickness at the midline, 1 1 mm.; behind the lateral teeth, 12 mm. As 

 in the type of E. wyomingensis, there is, on the upper surface, a broad longitudinal ridge 

 flankt by broad grooves. The thickening of the upper surface extends backward about 20 mm. 

 The width of the smooth band, at the hyoepiplastral suture, is 13 mm. There appears to be 

 neither reason nor profit in regarding E. jeanesi as distinct specifically from E. wyomingensis. 



The type of E. jeanesi was figured by Leidy. Diagrammatic figures are here presented 

 of both carapace (fig. 392) and plastron (fig. 393). 



An examination of the interior of the shell of this type shows that the inguinal buttresses 

 were not so strongly developt as in most other species of Echmatemys. They arise from the 



392- 



FIGS. 392 AND 393. Echmatemys wyomingensis. Carapace and plastron of type of 

 Emys jeanesi. Xj. U. S. N. M. 



391. Carapace. 



393. Plastron. 



floor of the plastron at a line two-fifths the distance from the free border of the hinder lobe to 

 the midline. The distances are respectively 29 mm. and 69 mm. The width of the smooth 

 band, on the upper surface, at the hypoxiphiplastral suture, is 12 mm. The greatest thickness 

 of the bone here is 13 mm. The axillary scute is mostly missing, but it appears to have 

 extended backward only to the middle of the fourth marginal. The inguinal scute too is 

 short, reaching forward only to the middle of the seventh marginal. 



No. 5988 of the American Museum furnishes the plastron complete and the carapace 

 lacking peripherals 3 to 6 inclusive, of the right side, the distal ends of the 4 posterior costals 

 of the same side, and the pygal. The specimen was obtained in 1903, on Little Dry Creek, 

 Wyoming, and belongs to horizon B. The shell has been crusht downward after burial and 

 the width considerably exaggerated. Both eleventh peripherals are present, but they stand 

 apart about 90 mm., whereas in life they were separated only by a pygal about 20 mm. wide. 



The surface of the shell was smooth. There is no suggestion of a median keel. The length 

 of the carapace (text-fig. 394) was close to 335 mm. The width may be regarded as having 



