S. W. Williston — North American Plesiosaurs. 235 



A front paddle preserved in the Yale collection, has, as usual, 

 the humerus more expanded distally. An outline of the cora- 

 coids and scapulae, as preserved, is given in text-figure 5. 



Polycotylus dolichopus n. sp. Niobrara Cretaceous of Kansas. 



A species quite distinct from P. latrpinnis is represented 

 in the Yale collection by two specimens, the one a femur and 

 most of the paddle (No. 1642), the other a humerus and some 



Figure 5. — Scapulae and coracoids of Polycotyhis latipinnis Cope. No. 

 1125, Yale Mtiseum. 



of the mesopodial and epipodial bones (No. 1646), both from 

 the Niobrara chalk of Kansas. 



I am convinced that these two specimens are conspecific, 

 judging especially from the shape of the epipodials, but in the 

 possibility that they may prove to be distinct, specimen No. 

 1646 may be considered the type of the species. The species 

 is especially characterized by the slenderness of the shaft of 



