PEECOMOKPHI. 87 



Tertiary strata of Green River, Wyoming; Dr. F. V. Hay den, Coll. 

 Mus. Smithsonian. 



In the original specimen of this species, but nine soft anal rays were 

 preserved; in a more perfect one, subsequently obtained, I find eleven or 

 twelve. I characterized a supposed species under the name of A. viridensis 

 on small specimens, one of which was stated to possess fourteen soft anal 

 rays. A re-examination of this fish leads me to believe that the separate 

 rods which represent this number are parts of but twelve rays. 



I have not seen the Asineops squamifrons from the Twin Creek locality, 

 where another species takes its place. 



ASINEOPS PAUCIRADIATUS Cope. 



BnUetin U. S. Geol. Snrv. Terrs., 1877, p. 813. 

 PI. XIV, fig. 1. 



This Perch is represented by a single specimen, which is larger than any 

 of those of the A. squamifrons, which have yet been found, and which is of more 

 robust proportions. It differs materially in the radial and vertebral formulae, 

 and in the greater relative shortness of the dorsal spines. I observe at 

 the base of these, a series of short subhorizontal basilar interneural bones. 



Foi-mulEe:— Radii: D.IX-12; A. II. 7. Vertebrae: D. 9; C. 13. One 

 or two vertebrae may be concealed behind the epiclavicle, but these, as in 

 the description of A. squamifrons, are uncounted. The depth enters the 

 length 2.25 times, the caudal fin being omitted. The length of the head is 

 little less than the depth. The dorsal spines are not very robust, and are 

 (excepting the first) of subequal length. The longest equals only half the 

 depth of the body at the middle of the second dorsal fin. The caudal is 

 rounded, and the ventrals are below the pectorals. The origin of the latter 

 is a little in advance of that of the first dorsal spine. Its base is attached 

 to four short basilar bones, of which the inferior two are stout in proportions 

 There are about ten rows of cycloid scales below the vertebral column. 

 Scales extend on the top of the head as far as the orbits. The mouth is termi- 

 nal. The total length of the type-specimen is ".243, of which the head 

 constitutes ".075. The longest (ninth) dorsal spine measures ".027, and 

 the second anal spine ".024. 



Twin Creek, Wyoming. 



