TKSTl'DINII)^:. 



393 



carapace about >^ mm. Its anterior extremity is broad and rounded. The distance between 

 the points where the pillar sulci cross the free border is l \J mm. The greatest thickness ot the 

 lobe, at the base of the lip, is 30 mm. There is a slight excavation at the base of the lip on the 

 upper surface. The edges of the anterior lobe are subacute. 



The posterior lobe has a length of 120 mm. and a width of 215 mm. at the base. The 

 thickness of the border of the hypoplastron just behind the inguinal notch is yj mm.; whereas 

 in .S. conspecta it is only 2} mm. The notch in the rear of this lobe has a depth of 25 mm. 



Figs. 498 and 499. Stylemys capax. Carapace and plastron of type. Xj. No. 1357 A. M. N. H. 



4'S . Carapace. 499. Plastron. 



The form and proportions of the scutes, upper and lower, do not differ in any important 

 way from those of S. conspecta. The humero-pectoral sulcus falls at a considerable distance 

 behind the border of the entoplastron, but this may be only an individual peculiarity. 



This species is remarkable for the thickness of the peripheral and plastral bones and for 

 the obtuseness of the free borders ot the anterior and posterior peripherals. The width also is 

 proportionately greater than that of S . conspecta, being onlv a little less than 80 per cent, of the 

 length of the carapace. 



Stylemys conspecta sp. nov. 



Plate 64, figs. I, 2; text-figs. 500, 501. 



Stylemys nebrascensis, in part. Cope, Vert. Tert. Form. West., 1884, p. 769. 



The type of this species is a large and fine shell which belongs to the Cope collection and 

 is now in the American Museum, bearing the number 1358. It was collected in 1878, by Mr. 

 Charles H. Sternberg, and appears to have been found near the junction of North Fork and 

 South Fork of the John Day River, in Grant Countv, Oregon. Its level is supposed to be the 

 middle beds of the John Day formation, the Diceratherium beds of Marsh. 



