[903-] 



Hay^ North American Cretaceous Fishes. 



5 



f- 



:ctK/ 



Ivom.t. 



In 1877, Cope, as cited, described from materials collected 

 in Gove County, Kansas, by Mr. Russell Hill, a species which 

 he called Erisichthe penetrans. The type, never figured 

 hitherto, is now in the American Museum. Its number is 

 2105. Views of this type, seen from below and from above, 

 and three cross- 

 sections are here 

 presented (Figs. 

 I and 2). The 

 specimen con- 

 sists of the snout 

 from the front 

 of the orbits 

 to the tip of 

 the rostrum, but 

 no other parts. 

 On the lower 

 side the surface 

 of the bone has 

 been damaged, 

 so that the or- 

 namentation is 

 removed over a 

 considerable 

 area; but where 

 preserved, it is 

 not especially 

 different from 

 that of the up- 

 per side. It is 

 somewhat coars- 

 er, and for a short distance in front of the vomerine fangs 

 forms areolae resembling those of the shell of Trionyx. 

 The specimen has suffered some crushing, and this affects 

 especially the region from the orbits to the vomerine fangs, 

 but also to some extent nearly the whole length of the rostrum. 



Cope has given the vertical diameter of the base of the ros- 

 trum as 20 mm., but this is not correct. The diameter is 





Fig. I. Protosphyrcena 

 nitida (Cope). No. 2105. 

 Type of Erisichthe pene- 

 trans Cope. Rostrum seen 

 from below. X 3. e/h., 

 ethmoid ; par., parasphe- 

 noid\vom., vomer; vom. /., 

 vomerine tooth. 



;. Protosphyrrena nitida 

 (Cope). No. 2105. Type of Eris- 

 ichthe penetrans Cope. Seen from 

 above. X 3. With cross-sections. 

 eth., ethmoid ; fr., frontal bone. 



