136 Illinois State Laboratory of Natural History. 



OXYGEKEUM gen. nov. 



Body long, subcylindrical, a little compressed, dorsal 

 behind ventrals, rudimentary caudal rays not unusually devel- 

 oped. Lateral line complete or nearly so; breast scaly; lower 

 jaw thin, with a sharp, hard edge; upper jaw protractile, with 

 a fleshy covering; no pseudo-branchia; pharyngeal teeth 5 5, 

 with grinding surface. Peritoneum black, intestine long, twice 

 or more the length of head and body. 



This genus seems most nearly allied to Acrochilus. from 

 which it differs especially in the absence of a horny plate 

 upon the upper jaw. 



PULVERULENTUM, n. S. 



In general form this species resembles a Moxostoma, hav- 

 ing the subcylindrical, slightly compressed body, deep caudal 

 peduncle, and posterior position of the dorsal of that genus, 

 but with a small conical head and large, terminal, oblique 

 mouth. A single specimen obtained is 2.5 inches long, the 

 depth 5 in length, caudal peduncle 4.2. The color in alco- 

 hol is light, slightly silvery on sides and belly, brightly so upon 

 cheeks and opercles. Back and upper part of sides finely lined 

 with brown or black, owing to the presence of a small brown 

 spot upon the middle of the front of each scale. The scales 

 on back and sides are finely and uniformly specked with black 

 over all their exposed surfaces, these specks being arranged in 

 concentric rows on each scale. They are more conspicuous 

 upon the lower part of the sides than above, and extend for- 

 ward upon the upper part of the opercle and the side of the 

 head, and even dot the iris of the eye. The head is pointed, 

 but slightly convex above, scarcely curved from the occiput to 

 the nostrils. It is contained 4.15 times in the length of the fish, 

 and its depth 1.35 times in its length. The nose is rather long, 

 3.13 times in head, slightly decurved, interorbital space 3.12. 

 The mouth is of moderate size, terminal, oblique, contained 

 2.7 times in length of head, the lower jaw a little the 

 shorter, thin and somewhat extended around the margin. The 

 upper lip is above the center of the eye; the upper jaw ex- 

 tends to the posterior border of the first nostril, and is con- 

 tained 3.4 times in head. Pharyngeal teeth 5 5, the three 

 anterior with grinding surface. The gill-rakers of the [interior 



