258 Bulletin 47, United States National Museum. 



NOTROPIS, (part): 



V. Scales loosely imbricated, not crowded along sides; teeth mostly without grinding 

 surface; no black spot at base of dorsal; caudal spot faint or wanting; fins 

 mostly plain or with red ; scales above lateral line usually large, in 5 to 7 

 series. 



TELESCOPUS; SOCIUS; NOTEMIGONOIDES; STILBIUS; ATHEBINOIDES; 

 ARGE; DILECTUS; FUMEUS; RUBRIFRONS; PHOTOGENIS; 



AMfENUS; SCEPTICUS; MICROPTERYX; METALLICUS, 481-494. 



LYTHRURUS, (\vOov, gore; 6vpe, tail): 



W. Scales more or less closely imbricated so that the exposed surfaces are deeper than 

 long; teeth with a narrow grinding surface; scales above lateral line small, 

 in 7 to 10 series, those before the dorsal reduced ; usually a dark spot on dor- 

 sal, rarely one at base of caudal ; males largely red. 



V. Dorsal fin without distinct dark spot, or at the most only a few punctulations.. 

 m'. Body short and deep. BELLUS, 495 



mm'. Body slender and elongate. LIRUS, 496. 



tt'. Dorsal fin with a black spot on its anterior rays, more or less distinct. 



'. Black dorsal spot above the middle of the fin. ROSEIPINNIS, 497. 



nn'. Black dorsal spot at the base of the fin. UMBBATILIS, 498. 



Subgenus AZTECA, Jordan & Evermann. 



400. NOTROPIS AZTECTJS, Woolman. 



Head 4; depth 3| to 4; eye 5; snout 3. D. 8; A. 8; scales 7-50-4, 

 about 23 before dorsal, small; teeth 4-4, hooked. Body rather stout, 

 heavy anteriorly, with long but strong caudal peduncle; back moder- 

 ately arched; head blunt and heavy, but less gibbous than in JV. ornatus] 

 snout short, not much longer than eye ; jaws subequal ; mouth moderate, 

 quite oblique, the maxillary not quite reaching eye, the cleft of the 

 mouth chiefly anterior ; eye small; scales very small for the genus, not 

 closely imbricated. Fins all low ; dorsal small, inserted behind ventrals ; 

 pectorals short, not nearly reaching ventrals. Lateral line decurved. 

 Color, dark above, below this a silvery band, and still lower a dusky or 

 plumbeous lateral band; young with a faint plumbeous caudal spot; 

 fins all plain ; cheeks silvery ; sexes alike in color. Length 3 inches. 

 This species has the head formed much as in Notropis ornatus, but in 

 form of body, color, and in size of scales the two differ widely. Valley 

 of Mexico. Our specimens collected by Mr. A. J. Woolman, at the City 

 of Mexico, where it abounds in the canals. (Aztecus, Aztec.) 

 Codoma vittata, GIRARD, Proc. Ac. Nat. Sci. Phila., 1856, 195, Valley of Mexico, (Coll. Potts.); 



and U. S. & Mex. Bound. Surv., Ichth., 53, pi. 29, figs. 18-21, 1859. 

 Notropis aztecw, WOOLMAN, Bull. U. S. Fish Comm., xiv, 1894, May 3, 1894, 63, plate 2, City of 



Mexico. (Type, No. 45569. Coll. Woolman.) 

 Cliola vittata, JORDAN & GILBERT, Synopsis, 172, 1883, (not Leuciscus vUtaius, DE KAY, 1842, which 



is also a Notropis). 



Subgenus CHRIOPE, Jordan. 



401. NOTROPIS BIFRENATUS (Cope). 



Head 4f; depth 4; eye 3. D. 8 ; A 7 ; scales 5-36-3 ; teeth 4-4. Body 

 rather slender, the caudal peduncle somewhat contracted. Head moder- 

 ate, the muzzle very obtuse. Mouth oblique, the jaws about equal ; 

 upper lip opposite lower part of pupil. Eye large, longer than snout. 

 Lateral line developed for a very short distance. 13 scales before dorsal. 



