EMYDID^. 303 



Survey, page 629. This bone (fig. 383) has a length of 23 mm., a width of 30 mm., and a 

 thickness of 6 mm. It is quite certain that it does not belong with the other bones of the lot, 

 all of which belonged to smaller turtles. In this lot are peripherals which belong to E. megau- 

 lax, having the scutal sulci deeply imprest. On some costals and a neural present they are not 

 so .deeply imprest. To the writer it appears that the peripherals are to be taken as the type of 

 this supposed species, and that these belong to E. megaulax. 



Cope (his plate xviii, fig. 33) has figured a costal bone, apparently the sixth of the left side. 

 The thickness of the posterior border is only 2.5 mm. while that of the anterior border is 7 mm. 

 This great thickness indicates that it united with the fifth costal to form a ridge for a strong 

 inguinal buttress. For this reason the species is referred provisionally to Echmatemys. The 

 proximal end of this costal shows that the sixth neural was short, 12 mm., at the costal border; 

 also that the fifth neural was probably octagonal. On this costal just outside of the area of the 

 fourth vertebral scute, there is a prominent boss. 



So far as known at present, this species differs from E. testudinea in having the neurals 

 keeled and the keel notcht at the crossing of the sulci; and in having the posterior peripherals 

 thin and deeply and broadly imprest by the sulci. It must be stated, however, that little is 

 known about the neurals of E. testudinea and little or nothing about the plastron of E. megau- 

 lax. It appears that the shell of E. megaulax was comparatively thin; that of E. testudinea 

 rather thick and heavy. 



Echmatemys testudinea (Cope). 

 Plate 45, figs. 16, 17; text-figs. 383-388. 



Notomorpha testudinea, COPE, Proc. Amer. Philos. Soc., XII, 1872, p. 475. 



Emys testuJineus, COPE, Sixth Ann. Report U. S. Geol. Surv. Terrs., 1872 (1873), P- ^ 2 7> Wheeler's 



Surv. W. looth Merid., iv, part ii, 1877, p. 58. 

 Emys testudinea, COPE, Vert. Tert. Form. West, 1884, pp. 129, 134, plate xxiii,figs. 12, 13. HAY,Bibliog. 



and Cat. Foss. Vert. N. A., 1902, p. 448. 



Professor Cope states that this species was represented in his collection by 4 or more 

 individuals. These he secured in the Green River beds, as stated on his labels, n miles east 

 of Evanston, Wyoming. These beds are a portion of the Wasatch formation. All the indi- 

 viduals collected by Cope were imperfect and fragmentary. Of his specimens he presented 

 figures of only an entoplastron and the left border of the hinder lobe of a plastron seen from 

 above. These figured specimens are now in the National Museum, at Washington, with the 

 catalog number 4103. 



In the Cope collection at the American Museum of Natural History there are several lots 

 of turtle bones bearing Cope's labels stating that they are Emys testudinea. Besides lacking 

 the figured specimens, these lots contain occasionally bones of more than one individual, and 

 we can not always be sure that they do not include parts of other species. To add to the con- 

 fusion, Cope's table of measurements (Tert. Vert., p. 135) can hardly be relied on; for while 

 he gives the width of the plastron at the axilla as 86 mm., which is probably correct, he states 

 that the length of the plastron from the axilla is approximately 50 mm. Whether this is an 

 error or whether he referred to the anterior lobe alone, it is impossible to say. In that table 

 the thickness of the hyoplastron at the entoplastron is said to be 99 mm. and at the hypoplastron 

 as 5 mm., both of which statements are obvious errors. What the facts were we can only 

 surmise. 



In one lot, that bearing the American Museum's catalog number 1178, there are found 

 the proximal ends of two costal plates, almost certainly the third and the fourth of the right 

 side (plate 45, fig. 16). These are probably the ones mentioned by Cope in his description of 

 1884 as belonging to his second specimen. The fourth has a width of 17 mm., the fifth a 

 width of about 20 mm. As stated by Cope, the sulci run in grooves. These grooves are broad, 

 while the sulci themselves are very narrow. The surface of these costals is swollen just outside 

 the sulci, forming what Cope has called a "hump." The thickness of the fourth thru this 

 hump is 8 mm. Where this costal articulated with the neural the thickness is 7 mm., while 

 that of the fifth is 8 mm. The rib-heads were not strongly developt. The external surface of 

 .these bones shows the lines of growth of the horny scutes. The sulci which limited laterally 

 the second and the third vertebral scutes run at- a distance from the neural border of only 5 



