22 
ZOOLOGY. 
5. ACOMUS GRISEUS, Grd. 
Gen. Rep. 222.—Plate XLIX, Figs. 5—9. 
Spec Char. —Head constituting the fifth of the entire length. Mouth moderate sized. Granules of lower lip largest close 
to the mouth. Eye small, sub-elliptical; its longitudinal diameter entering about seven times in the length of the side of the 
head. Anterior margin of dorsal fin equidistant between the extremity of the snout and the insertion of the caudal. 
Extremities of ventrals not reaching the vent; their origin taking place under the posterior third of the dorsal. Greyish brown 
above; whitish or yellowish beneath. 
259. Sweet water, tributary of Platte river, Nebraska. J. S. Bowman. 
6. PIMEPHALES MACULOSUS, Grd. 
Gen. Rep. 234. 
Spec. Char. —Body rather short, deep, and compressed; greatest depth equal to one-fourth of the total length, whilst the 
head constitutes the fifth part of it. Eye moderate and circular; its diameter entering four times in the length of the side 
of the head. Angle of the mouth not extending as far as a vertical line drawn in advance of the orbit. Extremities of 
ventrals overlapping the vent, and reaching the anterior margin of the anal. Scales much deeper than long, and larger on the 
peduncle of the tail than anteriorly. Yellowish brown with black blotches. 
153. Sluice of Arkansas river. Mr. Kreuzfeld. 
7. PIYBOGNATHUS PLACITUS, Grd. 
Gen. Rep. 236. 
Spec. Char.— Body sub-fusiform in profile. Head sub-conical, contained about five times and a half in the total length. 
Eye moderate sized, sub-circular. Anterior margin of dorsal fin nearer the extremity of the snout than the base of the 
caudal, whilst the insertion of the ventrals is nearly equidistant between the same points. Scales anteriorly rounded. Greyish 
brown above, silvery on the flanks, and dull metallic white beneath. 
89. Sluice of Arkansas river near Fort Makee. Mr. Kreuzfeld. 
8. HYBOGNATHUS EYANSI, Grd. 
Gen. Rep. 236. 
Spec. Char. —Body sub-fusiform in profile. Head sub-conical, thickish, contained about five times in the total length. Eye 
moderate sized, sub-circular. Anterior margin of dorsal fin equidistant between the extremity of the snout and the base of 
the caudal. Insertion of ventrals being situated posteriorly to the anterior margin of the dorsal, is therefore nearer the base 
of the caudal than the extremity of the Bnout. Caudal fin constituting the fifth of the total length. Scales anteriorly truncated. 
Reddish brown above ; silvery on the flanks and beneath. 
90. Sweetwater, tributary of Platte river. J. S. Bowman. 
9. ALGANSEA OBESA, Grd. 
Gen. Rep. 239. 
Spec. Char. —Head contained four times and a half in the total length. Eye rather small; its diameter entering nearly six 
times in the length of the side of the head. Posterior extremity of the maxillar bone corresponding to a vertical line drawn 
behind the nostrils. Anterior margin of the dorsal fin nearer the insertion of the caudal than the extremity of the snout. 
Insertion of ventrals nearer the base of the caudal than the extremity of the snout. Scales moderate. Bluish grey above; 
yellowish beneath; sides greyish. Fins greyish olive. 
193. Humboldt river. J. S. Bowman.—194. ?. Mr. Kreuzfeld. 
