386 Annals of the Carnegie Museum. 



Cotypes, No. 2S~2a-m, 5 females, 2.5 cm. to 3 cm.; 8 males, 2 cm. 

 to 2.4 cm.; Serrinha Parana, in a creek of Rio Iguassu, Dec. 24, 1908. 



No. 28710-^, 5 females, 2.5 cm. to 3.25 cm.; Porto Uniao da 

 Victoria, Rio Iguassu. 



No. 28700-0, 8 males, 2.1 cm. to 1.8 cm.; 7 females, 2.6 cm. to 

 2.8 cm. Porto Uniao da Victoria, Rio Iguassu, Dec. 27, igo8. 



No. 2873, 16 males, 1.5 to 2 cm.; 11 females, 2 cm. to 3.5 cm.; 

 Arroyo Miguelete, Montevideo, February 17, 1909. 



No. 2874, 10 males, 1.9 to 1.4 cm.; 13 females, 1.5 to 2.5 cm.; 

 Uruguayana, Brazil, February 6, 1909. 



D. 8; A. 8; P. 9; V. 5 or less; lower jaw somewhat longer, one com- 

 plete series of closely set chisel or narrow incisor teeth unhooked; 

 scales 29 to 32 in a median lateral series; body rather elongate, slightly 

 compressed in front and depressed posteriorly. 



Depth 3.5; head 4 2, diameter of eye 3 in length of head and slightly 

 greater than the length of the snout. The anal of the males is 

 much nearer the tip of snout than the base of caudal. The front edge 

 of first prolonged anal ray (the third anal ray) has a patch of fine 

 teeth located about one-third of the distance from the tip to the base. 

 The mouth opens above. The dorsal is inserted behind origin of anal 

 and about half-way between the base of caudal and posterior edge of 

 opercular flap. The lins are all colorless and the ventrals are very small. 

 The sides are without spots, or with from one to nine blotches or spots 

 (most frequently there are nine). The older females are dark above 

 and have light-colored abdomens. The males are always smaller and 

 have a circular dark anal ring, prolonged as a dark median black line 

 along the keel of caudal peduncle. 



I take great pleasure in dedicating the species to Mr. Andrew Car- 

 negie. 



Genus Characidium Rheinhardt. 



II. Characidium fasciatum Rheinhardt. 



No. 2875, Serrinha Parana, and No. 28760-6, Porto Uniao da 

 Victoria, Rio Iguassu. Above the Iguassu Falls in the Iguassu 

 River. 



D. 10 or II ; A. 7; P. 10; V. 9; length 4.4 cm.; depth i cm.; head 

 I.I cm. long; eye .3 cm., which is a little greater than the length of 

 the snout; pectoral 1.3 cm. long; head 5 in total length; eleven or 

 twelve scales between origin of dorsal and head; lateral line 4.5 to 5-36 

 to 38-3; lateral line complete or nearly so; pectorals reaching base of 



