8 Annals of the Carnegie Museum. 



from the center to the posterior border on a long gradual slope. The 

 outline of the anterior border of the left side is somewhat distorted 

 from the healing of an old wound. (See PI. I, fig. i.) Most of the 

 sutures can be clearly traced, but the sulci marking the limits of the 

 epidermal scutes, e.xcept on the ventral areas, cannot be determined in 

 either specimen, and as to the extent of the dorsal scutes we must 

 await the discovery of additional material. 



The carapace is 252 mm. long on the midline, and 178 mm. wide. 

 Compared with a specimen of Glyptops plicatulus in the U. S. National 

 Museum (Cat. No. 5458) the shell is more depressed and more elongate- 

 oval in its general contour. Anteriorly the border is excavated on 

 the midline and posteriorly it is evenly rounded with a narrow but 

 well-defined median notch. As in Glyptops plicatulus, there are eleven 

 peripherals, which extend outward nearly horizontally. Relatively 

 they are thin throughout the series, high on front and back, but narrow 

 above the bridges. The first and second have a height of 25 mm., 

 the fifth of 16 mm.; the ninth of 29 mm.; the eleventh of 26 mm. 

 Their borders are thin and acute in front and behind, but thicken and 

 become somewhat obtuse toward and above the bridges. Along the 

 sides and toward the front on the upper surfaces the peripherals 

 curve upward, thus forming a well defined gutter (best shown in speci- 

 men No. 3380, PI. II, Fig. i), which becomes wider and shallower 

 especially toward the posterior ends. The deepest part of this 

 gutter is in the center of the peripherals, whereas in G. plicatulus it 

 is confined to the outer half of their superior surfaces. 



The surface of the carapace is covered with small, rather obscure, 

 but irregularly placed tubercles and ridges, the latter on the median 

 part of the back having a tendency to run in a fore-and-aft direction, 

 but not forming a regular pattern. The sculpture of the carapace 

 would at once distinguish the species from G. plicatulus which as Hay^ 

 says, " is finely sculptured with tubercles and winding ridges, there 

 being about thirteen ridges in a line 10 mm. long." The surface of 

 the plastron and the lower surfaces of the peripherals and bridges in 

 the type of G. utahensis are smooth and without sculpture, which would 

 serve to further distinguish it from G. plicatulus, which is sculptured 

 beneath. In the second specimen, Cat. No. 3380, there is a decided 

 longitudinal depression or sulcus along the carapace where the second, 



1 Fossil Turtles of North America, Pub. Carnegie Inst., Washington, 1908, p. 49. 



