HYBOPSIS 163 



This is an active fish, decidedly preferring clear rocky streams. 

 Breeding males were taken about Ottawa in June. It has been 

 seen to spawn in shallow running water, piling pebbles up about 

 the nest after the eggs are deposited. Spring males have the front 

 of the head and the occipital region finely tuberculate. 



Genus HYBOPSIS Agassiz 



Bodv robust or elongate; mouth terminal or inferior; a barbel always 

 present, terminal on the maxillary (in one species there are 2 barbels on 

 each side); premaxillar\" protractile; teeth 4-4, or 1, 4-4, 1 or 0, hooked 

 and with grinding svirface narrow or obsolete; intestine short; peritoneum 

 pale, dusky, or black; dorsal rays 7 or 8; anal 6 to 8; scales 35 to 60; lat- 

 eral line continuous. Species numerous, about 17 ; 5 in Illinois. A large 

 and varied group, embracing both small species from 2| to 5 inches in 

 length and larger forms up to a length of 10 or 12 inches. United States 

 east of the Rockies; one species from California. 



HYBOPSIS HYOSTOMUS (Gilbert) 



Gilbert, 1884, Proc. U. S. Nat. Mus., 203 (Nocomis). 

 M. v., 64; J. & E., I, 316; L., 19 (part). 



Very small minnows with an inferior mouth, and with barbel ^ to ^ as 

 long as snout, easily distinguished among Illinois Cyprinidce by their 

 small size, elongate eye, posteriorly placed mouth (tip of lower lip 

 under first nostril), and rusty- to blackish-punctulate coloration. 

 Length of our largest specimens If inches; body moderately elongate, 

 subfusifonn, little compressed, heaviest forward of dorsal fin; depth 4.9 

 to 6.2 in length ; caudal peduncle slender, its depth 2.5 to 2.8 in its 

 length. Color silvery, everywhere more or less dusted with brownish 

 specks ; similar but larger specks, suggesting rust-spots in preserved mate- 

 rial, found on nose, suborbitals, and opercles; fins all pale. Head rather 

 long, 3 . 7 to 4, its width 2 to 2 . 1 in its length; interorbital space nearly 

 flat, 3 . 5 to 4 in head; eye 2 . 8 to 3 .4, elliptical, its long diameter IJ to 1^ 

 times its short; nose 2.7 to 3.1, about as long as eye, broad, bluntly 

 pointed and decurved, projecting nearly half its length beyond the mouth ; 

 mouth wholly inferior and horizontal, tip of lower lip directly under first 

 nostril; maxillary 3 . 3 to 3 . 8 in head, reaching past front of orbit; barbel 

 long, 2 to 3 in snout; isthmus less than pupil. Teeth 4-4, rather strongly 

 hooked, the grinding surface extremely narrow or not at all developed; 

 peritoneum silvery, with some rather coarse specks upward. Dorsal fin 

 with 8 rays, rarely 7, set about over ventrals and equidistant between 

 muzzle and base of caudal; longest dorsal ray 1.1 to 1.3 in head; anal 

 rays 7 or 8, usually 7; pectorals more than § to ventrals; ventrals past 

 vent. Scales 5, 34-36, 4; 14 before dorsal; lateral line decurved. 



Sexual differences not noted, our specimens being few and probably 

 not fully grown. 



