384 University Geological Survey of Kansas. 



veloped, but the posterior was probably composed of only a few 

 feeble spines, which were probably not preserved in the speci- 

 men described by Professor Cope. 



Syllsemus latifrons. Plate LXXII, fig. 2. 



Syllcemus latifrons Cope, Rep. U. S. Geol. Surv. Terr., vol. II, p. 181. 



This species is represented by only two specimens in our col- 

 lection, from the Fort Benton Cretaceous, the exact locality of 

 which is not known. 



The body is elongate and slightly larger than that of Leptich- 

 thys. The head is broad, flat, and, so far as can be determined, 

 the frontals form the greater part of the roof of the skull. They 

 are separated medially by a well-marked suture and possess no 

 markings. The orbits are large and the skull is rather acutely 

 pointed in front. The dentaries are short and seem to be with- 

 out teeth. The opercular bones are large and are directed well 

 downward. The pectoral fin is situated rather inferiorly, and 

 is made up of numerous small rays, fifteen to twenty in num- 

 ber, which are strongly bent at the proximal ends. The ante- 

 rior dorsal fin is short, and is made up of thirteen or more rays. 

 The posterior dorsal is small, and with but few rays, which 

 seem to be well separated from each other. The pelvic fin is in 

 too poor a state of preservation to determine its characters, and 

 the caudal fin is broken away in both of our specimens. Verte- 

 brae longer than deep, about thirty-six present. 



Length of specimen to base of caudal fin (estimated) 315 mm. 



Length of specimen to base of dorsal fin 132 " 



Length of specimen to base of pectoral fin 90 " 



Depth of body at anterior dorsal fin 69 " 



Length of mandibular rami 39 " 



Length of skull 70 " 



Width of skull posteriorly 33 " 





