256 Bulletin 47, United States National Museum. 



Alburnoi'S, (i(?6j(ni».<, tho bleak, from n/frnv, white; uji//, appearance): 

 ee. Lateral line always coniplcto; scales large, fewer than 40 in lateral line; 

 teeth 4-4, well hooked. Small, weak species. 

 it. Body rather elongate, the depth not more than 3^ the length. 

 I. Scales before the dorsal 17 in number; aspect of N. helerodon. 



FllETENSIS, 407. 



U. Scales before the dorsal 12 to 15 in number. 



m. Body not marked with distinct round dark spots; the spots, if 

 any, mere punclulations. 

 n. Base of caudal without distinct black spot, (except iu the 

 very young). 



BLENNIUS; SABIN/H; VOI.UCEI.LITS; SCYLI.A; PROCNE; 

 NIDROT.KNIATUS; and KANAWHA, 408-414. 



nn. Base of caudal with a small black spot more or less dis- 

 tinct. 



BEAYTONI; SPECTEUNCULTJS; OZAKCANIS, 41.5-417. 



mm. Body with many irregular round black spots and dots, the 

 largest often nearly as large as pupil; form rather stout. 



CHIHUAHUA, 418. 

 kk. Body short ami chubby, the deptli more than 3:^ the length. 



TOl'KKA, 419. 



HuDSONius, (from Hudson Kiver): 

 cc. Teeth two-rowed, 1, 4-4, or 1, 4-4, 1 or 2; the grinding surface more or less devel- 

 oped. 



o. Head comparatively large, zy.^ to 4}/^ in body; teeth, 1, 4-4, 1; small, slen- 

 der species, without distinct dark spot at base of caudal. 

 p. Eye moderate, 'A]A to 4 in bead iu adult. 



GILBEtlTl; PIPTOLEPIS; SIMUS; LONGIROSTRIS, 420-423. 



pp. Eye very large, 3 to 33^ in head in adult. 



Nux; NocoMis; shumardi; illecebrosus, 424-427, 

 00. Head short, bluntish, 4 to 5 in body in adult; species of large size and sil- 

 very coloration, usually with a distinct black spot at base of caudal fin. 



HunsoNius, 428. 

 bh. Scales deeper than long, more or less closely imbricated along sides of body; teeth with 

 the edges often crenate, the grinding surface sometimes narrow or obsolete. 

 q. Teeth one-rowed, 4-4, the young sometimes 1, 4-4, 1. 

 CoDOMA, (a coined name): 

 r. Head very thick, bluntly rounded on every side; mouth small, oblique, its 

 cleft chiefly anterior; scales large, about 40 in lateral line, oknatus, 429. 

 MoNlA-NA, (a coined name): 



rr. Head compressed, not bluntly rounded. 



s. Dorsal without distinct black blotch on its upper posterior portion; body 

 more or less deep and compressed. 

 (. Scales small, 43 in lateral line; a dusky spot at base of caudal. 



FORMOSUS, 430. 

 tt. Scales moderate, 33 to 38 iu lateral line; adult without caudal spot. 



FRIOIDUS; LUTRENSIS; PROSERPINA, 431-433. 



4S. Dorsal with a black spot on its last rays above, the fin very higli. 



CALLISEMA, 434. 



CyPRiNELLA, (diminutive of ('ijprUms, carp): 

 qq. Teeth two-rowed, 1, 4-4, 1. 



H. Anal fln moderate, of 7 to 9 rays. 



t'. Dorsal fin without large black blotch on its upper posterior rays in adult. 

 w. Caudal fin without black spot at its base in adult. 



X. Body deep, compressed, broadly elliptical in outline. 



BUBALINUS, 435. 

 XX. Body subfusiform in outline. 



LUDIBUNDUS; MACROSTOMU.S, 436; 437. 



