TISTl'DINII).*:. 



395 



No. 1354 of the Cope collection has a length of 219 mm. and a width of 160 mm. Its 

 anterior border is concave, the neurals are ot moderate width, the pygal is bifurcate, the 

 peripherals over the hind limbs somewhat flaring, and there is a conspicuous and sharp carina 

 along each side. The vertebral scutes are like those of No. 1359. There is a considerable 

 depression on the area of the second, third, and fourth vertebral scutes. No. 1355 is an injured 

 shell, but shows an anterior slightly concave outline. A peculiarity is presented in the anterior 

 neurals. The first is broad in front and comes into contact with the second costal plates. 

 The second is hexagonal, with the shorter sides behind. The third seems to have had four 

 convex sides. The anterior vertebral scute has been 64 mm. wide; the second, 52 mm. wide. 



No. 1351 is a small turtle, 145 mm. long, which has the first and fifth vertebral scutes 

 about as wide as the second and third. 



500. 



Figs. 500 and 501. Stylemys conspecta. Carapace and plastron of" type. 

 Xi No. 1358 A.M.N. H. 



500. 



(;oi. Plastron. 



Notwithstanding the differences observed among the specimens just described, the writer 

 feels compelled to refer them all to a single species. 



Stylemys conspecta appears to differ from S. nebrascensis in the following respects: The 

 shell is narrower in proportion to its length. The width forms about 75 per cent, of the length, 

 whereas in .V. nebrascensis, the width is usually, if not always, about 85 per cent, of the length. 

 In iS'. nebrascensis the second and third neurals are almost always hexagonal. Only in the 

 specimen described by Leidy as S. culbertsonu has the writer observed an octagonal second 

 neural. In only one specimen of S. conspecta, No. 1354, above described, has the second been 

 observed to be not octagonal, and this specimen has other irregularities. The costal plates of 

 S. conspecta are more highly differentiated than those of S. nebrascensis, as has been described. 

 The anterior peripherals ot S. conspecta do not extend so far backward from the free border 

 as those of S. nebrascensis. The position of the sulci between the anterior marginal and the 



