360 ZOOLOGY. 



pupil. Insertion of the ventral fins opposite the seventh ray of the dorsal. Caudal posteriorly concave. Dorsal fin ante- 

 riorly concave. Lower fins moderately developed. Scales deeper than long, grooved on all sides. Reddish brown above ; 

 silvery beneath. 



Stn. — C^rpiotks damalis, Gkd. in Proc. Acad. Nat. So. Fhilad. VIII, 1856, 170. — Ib. Gen. Rep. Fishes, 218. 

 A large number of these fish were obtained from sunken pools on Milk river, Nebraska. 

 When properly cooked they are not unpalatable. 



ACOMUS LACTARIUS, Grd. 



River S acker. 



Plate L. 



Sp. Cn — Head constituting somewhat less than the fifth of the total length. Mouth small ; lips well developed, covered 

 with uniform granules. Eye large, sub-circular ; its diameter entering five times in the length of the side of the head. 

 Anterior margin of dorsal fin somewhat nearer the insertion of the caudal than the extremity of the snout. Insertion of 

 ventrals situated opposite the posterior half of the dorsal ; their tip exteuding to the vent. Grayish brown .above ; grayish 

 white beneath. 



Syn.- Calostomtis [Acomus) ladarius, Gkd. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 174. 

 Aamiui lactaritis, Grd. Gen. Kep. Fishes, 223. 



This sucker was obtained by me in the lagoons along, the course of the upper part of Milk 

 river, Nebraska. At the season of the j^ear in which I visited that locality, the bed of the 

 river being dry in many places, these fish, with others, had retreated to deep holes and small 

 stagnant lagoons in great numbers. With a small seine I was enabled to take, in a very brief 

 space of time, many valuable ichthyological specimens, consisting of individuals of the present 

 species, besides other cyprinoids, pike, perch, &c., some of which were carefully preserved for 

 the national collection, and others afforded a welcome addition to our usual monotonous fare. 



CATOSTOMUS SUCKLII, Grd. 



Nebraska Sncker. 



Plate LI. 



Sp. Ch. — Head constituting the fifth of the entire length. Eye small. Mouth rather small ; lips moderately developed, 

 covered with conspicuous papilla;. Isthmus of medium width. Dorsal fin as high as long ; its anterior margin somewhat 

 nearer the insertion of the caudal fin than the extremity of the snout. Insertion of ventrals a little in advance of the 

 middle of the dorsal, and equidistant between the extremity of the snout and the fork of the caudal. Posterior extremity 

 of anal extending beyond the rudimentary rays of the caudal. Grayish olive above; yellowish olive beneath. 

 Syn. — Catos omus sucklii, Grd. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 175.— Ib. Gen. Rep. Fishes, 226. 



The present fish is not tincommon in the upper Missouri and its tributaries, in the same 

 localities as the last mentioned species. 



In 1854 I noticed in one of the branches of Snake river, Oregon, a sucker of about the same 

 size and of much the same general appearance as this. Its colors on the back, however, were 

 darker. Owing to a deficiency in the means of transportation, and to other causes, I was unable 

 to preserve this fish, which I regret the more because it was the only specimen of a genuine 

 sucker (catostomus) that I saw west of the Rocky mountains. 



PIMEPHALES FASCIATUS, Grd. 



Sp. Ch. — ^Body anteriorly stoutish, its depth being contained five times in the total length, in wliich the head enters four 

 times and a half. Eye moderate and circular, its diameter being contained somewhat more than four times the length of 



