858 FISHES—CYPRINIDA. 
Rhinichthys lunatus, Corr, Proc. Phil. Acad. Sci., 1864, 278; Journ. Phila. ‘Acad. Sci., 
1869, 228.—JorpDan, Ind. Geol. Survey, 1874, 223; Man. Vert., 281. 
Argyreus lunatus, Corn, Proc. Am. Phil. Soc., 1870. 
Description.—Body moderately elongate, little compressed ; head moderate, rather 
broad and flattened above; snout moderate; naouth small, horizontal, subterminal, the 
lower jaw included; barbel minute, but probably always present; upper lip on the 
level of the lower part of the pupil; maxillary not reaching nearly to the eye; eye 
small, nearly median, one and one-half in snout, four and one-half in head; fins rather 
small; dorsal fin well back; scales quite small, somewhat imbedded; lateral line 
decurved; color blackish above, some of the scales irregularly darker; a black band 
passing frem the snout through eye and along the sides of the body ; a pale streak below 
this; belly silvery; males in spring with the lateral bands and the lower fins, and some- 
times the whole body bright crimson; males in later summer with the lateral band 
scarlet or orange, the red color growing fainter later in the season; head 4; depth 435 
D.7; A.7; lat. 1.64; teeth 2, 4-4, 2. Length 3 inches. 
Var. obtusus (Ag.) a southwestern form may be thus characterized : 
Very similar to R. atronasus, but usually rather stouter, the head a little shorter, and 
the coloration somewhat different ; bask olivaceous, mottled with darker; sides with 
a rather faint brownish band margined above and below with paler; belly silvery; a 
dusky blotch in the middle of the base of the dorsal fia; males with the pectoral fins en- 
larged, and with the lateral band rosy ; head 4; depth 44; D. 7; A.7; scales 1463-8; 
teeth 2, 4-4,2. Length 3 inches. 
Habitat, New England to Alabama. Var. atronasus in the region from Cleveland east- 
ward to Maine and Virginia. Var. obtusus in the Upper Lake Region, Ohio Valley and 
southward to Georgia and Alabama. 
Diagnosis—This species may be known by its small scales and dark 
colors in connection with the position of the mouth. Its shorter snout 
distinguishes it at once from the preceding. 
Habits.—This species is one peculiar to the clear small brooks and 
spring runs. In suitable localities it is excessively abundant. It is a 
very swift and active fish, and the males in spring and summer are 
brilliantly colored. 
Genus 39. ERIMYSTAX. Jordan. 
Erimystax, JORDAN (nova). 
Type, Leuciscus dissimilis, Kirtland. 
Etymology, eri, an intensive particle ; mustax, barbel (moustache). 
Body elongate; mouth inferior, with the lips somewhat thickened ; a well developed 
barbel at the posterior end of the maxillary; teeth 4-4, hooked, with narrow grinding 
surface ; scales rather large ; lateralline continuous; dorsal fin in advance of ventrals ; 
anal basis short; sizo medium. A single species known, in coloration and habits bear- 
ing some resemblance to the Etheostomoid fishes. 
