NATIONS ACROSS THE GREAT BASIN OF UTAH. 



length of tin- maxillary, and are twice as long as the internal 



ul rays are enveloped in a thick skin: there are eight, of which 

 ittened and largest; the rest arc slender, and rapidly decrease in 

 tstegal membrane is deeply excavated, and is attached to the 



ane; the mental fold is itself midway between the emargination 



nmences at a third of the distance from the snout to the concave 

 IB : its base equals a fourteenth of the total length, and is scarcly 

 spine is slender, and about three-fourths of the length of the 

 ior margin is nearly edentulous, having but two or three tuber- 

 ;df. 



elongated and falciform, and nearly equals in length (or height) 

 real; its base is over the penultimate ravs of the anal tin. 

 mcnces at the titty-six hundredths of the distance between the 



margin of the caudal fin; it is situated one twenty -fifth of the 

 e anus. Its base is more than a fifth of the length of the fish; 



the in, 



p'Ttrri specimens 



before us) ,s somewhat greater than an eighth of the total length, and above two and 

 half times greater than that of the posterior rays. 



The pectoral fins have each a strong compressed spine, smooth on the external 

 margin, and armed with strong teeth directed downward on the internal one The 

 length is equal to thirteen hundredths of the total length, and that of the first articu- 

 lated and longest ray to fifteen hundredths. The process of the coraeoid bone pro- 

 jects beyond the base of the pectoral spine for a distance equal to the interval between 

 the snout and orbit. The ventrals commence between the fourth and fifth tenths of the 

 length: their length somewhat exceeds a tenth of the total. The second and third 



The caudal fin is deeply forked, the longest ray being at least twice as long as 

 the central ones: the latter form a ninth of the total length. The base of the fin is 

 ™"? x - . The nMm,,marv rays advance comparatively little on the superior and 



streams and rivets, but appears to differ from all of them. From the Ictahmts cteruhs- 

 cens (Fimclodus carulwrns Eat.) and Trtnhmts a[fims (Ph»rh,his afinns Girard) it is 

 at once distinguishable by the fewer rays of the anal fin, there bein- about thirty ravs 

 in that of the former and thirty-five in that of the latter. The distinction from the 

 Ietalurm oUraceus (Pimvhdus olivaccus Girard) and Ictalurus rulpcs ( Vhu-hihis rulpr* 



