342 



FOSSIL TURTLKS OF NORTH AMKRICA. 



The very narrow first vertebral scute distinguishes this species from all others, especially 

 from E. uintensis, which also comes from the Uinta formation. From many species it is dis- 

 tinguish! by the rather broad vertebrals succeeding the first. The narrow epiplastral lip and 

 the longitudinal ridge on the upper side of the symphysis are peculiarities. The femoral 

 scutes are unusually narrow at the midline. The species resembles somewhat E. septaria 

 (Cope), but the vertebral scutes of the two are different, and the epiplastron of E. callopyge 

 appears not to have been so greatly thickened as in E. septaria. 



Echmatemys uintensis sp. nov. 

 Plate 53, figs, i, 2. 



In the paleontological collection at Princeton University there is a fine, large shell of a 

 species of Echmatemys which was collected in 1895, by Mr. J. B. Hatcher, in the middle 

 Uinta formation, on White River, Utah. It bears the catalog number 11198. This shell is 

 practically complete and but little crusht. The total length, in a straight line, is 460 mm.; 

 the width, 295 mm.; the height above the bottom of the plastron, 160 mm. In outline the 

 carapace is somewhat concave in front, rounded behind. The hinder peripherals flare slightly 

 upward. 



On the nuchal bone and the anterior neurals there is a slight ridge; and this reappears and 

 is more prominent on the hinder third of the shell. 



The nuchal bone is 67 mm. long and 107 mm. wide. It is excavated behind for the first 

 neural. The neurals are relatively broad, the second, third, and fourth hexagonal; the fifth 



octagonal, joining the fourth, fifth and 

 sixth costals; the sixth and seventh 

 broadly hexagonal; the eighth nearly 

 quadrate. The table shows the dimen- 

 sions of the neurals. 



The first suprapygal is 37 mm. long, 

 21 mm. wide in front, and 42 mm. wide 

 posteriorly. The second is 47 mm. long 

 and 1 15 mm. wide. 



The first peripheral has the free edges 

 moderately acute, but toward the axil- 

 lary notch the others become obtuse. 

 All these rise above the free margin about 

 60 mm. The eighth peripheral is 67 mm. high. The pygal is 42 mm. wide and 38 mm. high. 

 The vertebral scutes are longer than wide with the sides nearly straight, except where the 

 sulci dividing the costal scutes are given off. The dimensions of these scutes are given above. 

 The anterior suprapygal is 37 mm. long, 21 mm. wide in front, and 41 mm. behind. The 

 second suprapygal is 49 mm. long, 105 mm. wide across the middle, 33 mm. where it joins the 

 pygal. The hinder boundary of the fifth vertebral scute lies on the second suprapygal. 



The axillary and inguinal buttresses rise high within the carapace, but the details are not 

 known. They extend at their bases but a short distance inward beyond the free borders of 

 the plastron. 



The anterior lobe of the plastron is 120 mm. long and 200 mm. wide at the base. From 

 the axillae the width decreases slowly to just beyond the hyoepiplastral suture, then more 

 rapidly by a sigmoid curve to the lip. The latter is 65 mm. wide and truncated. It projects 

 little beyond the ends of the gulo-humeral sulci. As seen from below, it is convex from side to 

 side; as seen from above, concave. The thickened portion of the lip continues backward 

 30 mm.; and behind it the thickness is not greatly reduced. The free border of this lobe is 

 acute. On the upper surface of the bone the horn-covered surface is 23 mm. wide. 

 The entoplastron is diamond-shaped, 70 mm. long and 95 mm. wide. 



The hinder lobe is 150 mm. long and 200 mm. wide at the base. The notch in the hinder 

 end is ) 6 mm. deep and 55 mm. wide. The border of the lobe is acute. Seen from above, the 

 beveled surface is 37 mm. wide at the hypoxiphiplastral suture; at the femoro-anal sulcus 

 only 15 mm. At the inner border of the bevel the thickness is 20 mm. 



