126 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 56. 



American Museum of Natural History and at least two, Nos. 4061 

 and 4121, the former, which was figured ^ by Cope, now belongs to 

 the United States National Museum collections. These cotypes and 

 other specimens were collected in the Green River beds of the 

 Wasatch formation, at Black Buttes, Wyoming. 



In 1908 Hay ^ redescribed these cotypes and other materials and 

 figured some additional parts. 



The typical material is quite inadequate so far as giving a clear 

 conception of the bony structure and the true relationships of the 

 species, and the provisional recognition of a more perfect specbnen 

 in the United States National Museum collections here referred to 



■'Xolp' 



Figs. 6 and 7.— Echmatemys megaulax (Cope). No. 7316 U. S. N. M. (6). Carapace. .V. /, 2, 3, 4, 

 S, 6, 7, 8, neural bones one to eight nu. nuchal ,7)., Pla.stron, ab., abdominal scute., 

 an., anal scute; ent., sutural surfaces for entoplasthon; fern., femoral scute; hum; 

 humeral scute; hyo., hyoplastron; hypo., hypoplastron; xiph., xiPmPLASTR3N. Both 



FIGURES one-half NATURAL SIZE. 



Echmatemys megaulax (Cope) is a welcome addition to our knowledge 

 of this species. 



This specimen (No. 7316) was collected by Mr. D. F. Hewett of 

 the United States Geological Survey in 1911 from the Wasatch forma- 

 tion, in sec. 9, T. 50 N., R. 99 W., near Wiley, Big Horn County, 

 Wyoming. It consists of a considerable portion of the carapace and 

 plastron as shown in Plate 36, as well as the humerus and ulna of 

 the right side. 



The principal portions missing are all of the peripherals posterior to 

 the third, posterior half of the eighth neural, suprapygal, pygal, seventh 

 and eighth costals of the right side and the eighth of the left side; 



» Vert. Tert. Form. West., 1884, pp. 129, 132, pi. IS, figs. 26-33. 



« Fossil Turtles of North America, Pub. Carnejrte Institution, 1908, pp. 301, 303, pi. 45, figs. 14, 15, text 

 flg. 380-383. 



