84 THE WASATCH AND BRIDGER FAUN^. 



Amphiplaga bkachyptera Cope. 



Bulletin U. S. Geol. Surv. Terrs., 1877, y,. 812. 



Radii: D. II — 8; A. Ill — 4. Vertebrae of the caudal series 15. Scales: 

 transverse row, 22; longitudinal row behind first interneiiral bone, 40. The 

 only specimen I possess lacks the head, so that various characters cannot 

 be ascertained. The depth of the body at the first dorsal spine enters the 

 length from that point to the base of the caudal fin two and a half times, 

 giving a general form of medium proportions. Caudal peduncle stout. 

 The vertebrce are contracted medially, and not shortened; they have two 

 or three longitudinal keels, which are somewhat irregular in their connec- 

 tions. This species is larger than any of the Erismatopteri yet known. 



Measurements. ^ 



u. 



Length from first dorsal spine 073 



Length from first anal spine 051 



Length of aual fin 023 



Length of second dorsal spine .' 015 



Length of third anal spine 013 



Depth at first anal spine 018 



From the Green River shales at Twin Creek, Wyoming. 



ASINEOPS Cope. 



Proceed. Amer. Philos. Soc., 1870, p. 380. Annnal Report U. S. Geol. Snrv. Terrs. , 1870, p. 425. 



Branchiostegal radii, seven; ventral radii I. 6-7. Opercular and 

 other cranial bones unarmed; scales cycloid. Spinous and cartilaginous 

 dorsal fins continuous; caudal rounded; anal with two spines. Lateral line 

 distinct. Operculum with regularly convex posterior border. Teeth coarsely 

 villiform, without canines. Both spinous and soft portions of dorsal and anal 

 fins moderately scaly. 



This well marked genus is established on the remains of numerous 

 individuals, in various states of preservation, so that the characters undis- 

 tinguishablo in one can be discovered in another. Thus the lateral lino is 

 preserved in one only, and the teeth in another. In none can I be entirely 

 sure that I see the vomer. 



The scales are preserved in many specimens, and I cannot find a 

 ctenoid margin in any, nor any radiating sculpture, but delicate concentric 



