/ora'an and Kveriiiaiin. — Fishes of JVorth America. 209 



5-5, scarcely hooked, cultriforni, with rather broad but shallow grinding 

 surface, the largest standing iii> well above the surface of the bone. Gill 

 rakers rather long and slender; psendobranchia) large. Si/e largo One 

 species. American. (Laviiiia, a classical name, without special applica- 

 tion to these fishes.) 



333. LAVINIA EXILICAUDA, Baird & Girard. 



(Hitch; Chi or Chigh.) 



Head 41; depth 3J^; eye 4. D. 10; A. 12; scales 13-64-8; teeth 4-5 or 

 ,">-5. Body deep, compressed, tapering to the caudal peduncle, which is 

 very slender. Upper lip on the level of the lower part of the pupil, the 

 maxillary falling short of the eye. Preorbital short and deep; suborbital 

 moderate. Eye rather large, anterior. Scales rather large, 42 in front of 

 dorsal. Dorsal tin rather small; pectorals short; anal high and long; 

 caudal well forked, its rudimentary rays strong, about ten in number. 

 Color dark above, sides somewhat silvery; scales with dark specks. 

 Length 12 inches. Streams of the Coast Range about San Francisco and 

 Monterey, locally common as far north as Clear Lake, (exilis, slender ; 

 Cauda, tail.) 

 Lavinia exiUcauda, Baird iind Girarh, Proc. Ac. Nat. Sci. Phila., 1854, 137, Sacramento River, 



California. (Type, Nos. 207 and 209. Coll. Heermami.) Girard, Pac. R. R. Surv., x, 241, 



1858. Jordan i Gilbert, Synopsis, 153, 1883. 

 Lavinia harengiis, Girard, Proc. Ac. Nat. Sci. Phila., 1856, 184, Monterey, California. (Type, 



No. 210. Coll. A. S Taylor.) 

 LeuciscM exilicauda, Gunther, Cat., vii, 248, 1868. 



105. CHROSOMUS, Rafinesque. 



Chrosomus, Rafinesque, Ichth. Oh., 4", 1820, (eryOirogaster). 



Body moderately elongate, little compressed. Jaws normal ; no barbel ; 

 teeth 5-5 or 4-5, moderately hooked, with well-marked grinding surface. 

 Alimentary canal elongate, about twice as long as body; peritoneum 

 black. Scales very small. Lateral line short or wanting. Dorsal behind 

 ventrals; anal basis short. Size small. Colors in spring brilliant, the 

 pigment bright red. This genus is of somewhat doubtful relationshi}), 

 and shows many analogies with the subgenus Phoxinms under Leuciscus. 

 (vpwr, color ; ctw/u«, body.) 



a. Lower black lateral band extending backward to base of caudal. 



b. Lower black band ending iu a black spot. erythrogaster, ;!:M. 



hb. Lower black band broader, and not ending in .a black spot. dak(itexsis, :!).''>. 



aa. Lower black lateral band extending downward and backward, ending above base of aii.il, 



the upper band forming the black caudal spot. oreas, SM. 



334. CHROSOMUS ERYTHROGASTER, Rafinosque. 

 (Red-bellied Dace.) 



Head 4; depth 4. D. 7; A. 8; scales 16-85-10; teeth usually 5-5. Body 

 oblong, little compressed, tapering each way from the middle. Head 

 moderate, rather pointed. Mouth moderate, terminal, oblique, the jaws 

 about e(|ual. Fins rather small ; the dorsal and anal high and short ; 



F. X. A 15 



