GILMORE: the fossil turtles of the UINTA FORMATION 157 



stack Mountain, Wyoming, so that the discovery of the present specimens in the 

 Uinta formation of Utah, considerably extends the geological as well as the geo- 

 graphical range of this species. 



18. Amyda scutumantiquum (Cope). 

 Plate XXVI, fig. 2. 



Trionyx scutumantiquum Cope, 6th Ann. Report U. S. Geol. Surv. Terr., 1872 

 (1873), p. 617; Amer. Naturalist, XVI, 1882, p. 988, fig. 6; Vert. Tert. Form. 

 West., 1884, pp. 118, 121, PI. XVI, figs. 1, la; Hay, Bibhog. and Cat. Foss. 

 Vert. N. A., 1902, p. 454. 



Amyda scutumantiquum Hay, Amer. Geologist, 35, 1905, p. 336; Fossil Turtles of 

 North America, 1908, pp. 521, 522, plate 100, figs. 2-4, plate 101, fig. 1; text- 

 figs. 676, 677. 



A very large specimen C. M. No. 3272 (see plate XXVI, fig. 2), consisting of a 

 considerable part of the anterior two-thirds of the carapace, is identified as per- 

 taining to the above genus and species. This specimen was collected by Earl 

 Douglass May 25, 1908, from the lower portion of Horizon B, "transition beds 

 sandstone," Uinta formation. Upper Eocene, as exposed on the south branch of 

 Red Bluff Wash, above the well on the stage-road between Bonanza and Kennedy's 

 Hole, Uinta County, Utah. 



This specimen lacks all of the carapace posterior to the fifth costals, the 

 anterior border and left end of the nuchal, and small portions here and there of the 

 costals forward of the sixth. The sandstone matrix containing the impressions of 

 the seventh and eighth costals fortunately is preserved and serves to give a fairly 

 accurate idea of the dimensions of the entire shell. 



In form the carapace is broadly oval with the length shghtly exceeding the 

 breadth. The greatest width, as in the type, appears to have been at the middle. 

 The extreme width is about 530 mm.; the length, at the very least, was 570 mm. 

 The shell is broadly arched from the lateral borders to beyond the middle of the 

 costal plates. Along the middle of the back there is a pronounced longitudinal 

 depression which is deepest at about the middle of the shell. 



The nuchal extends on each side of the midline about 180 mm.; its width on 

 account of the missing anterior border cannot be given. At the center on the 

 broken border the nuchal has a thickness of 23 mm. Its outer end is bevelled off 

 toward the front and outer extremity. The length of the nuchal is .74 the width of 

 the shell, whereas the type of the species is .76 (not .80 as stated by Hay). 



