236 Annals of the Carnegie Museum. 



Body elongate, compressed; dorsal profile more or less arched, head 

 moderate, its top very slightly arched; snout bluntly pointed anteriorly; 

 mouth oblique, its angle extending to a vertical through anterior 

 border of orbit; lower jaw slightly shorter than the upper; eye moder- 

 ate, superior; nostrils close together, in front of eye, anterior nostril 

 in a short tube; lower part of pre-operculum and sides of the snout 

 with a number of colorless tubercles; extremity of the snout, upper lip, 

 and outer part of lower jaw with a series of minute tubercles. 



Origin of dorsal nearer tip of snout than base of caudal, opposite 

 the ventral, short, rather high, but not exceeding the length of head; 

 pectoral elongate, extending beyond the root of ventral; ventral fin 

 rather short, reaching the root of anal; anal fin elongate, its middle 

 ray much longer than the head, when depressed reaching beyond the 

 root of caudal, two or three of the anal rays provided with tubercles; 

 caudal fin strongly bifurcated; depth of caudal peduncle 2.4 in length of 

 head. 



Scales thin and cycloid; lateral line decurvcd, extending along the 

 lower half of the tail. 



Color in alcohol brownish gray above, paler below; lower parts 

 silvery; sides with about twelve dark cross-bars; membrane of dorsal 

 and anal fins with a series of black streaks; dorsal and caudal fins 

 dusky; the pectoral and ventral whitish. 



Total length 120 mm. 



Described from a specimen from Choso River near Koshiryo, 

 collected by T. Aoki in i\ugust, 1917. 



Habitat: Tamusui River (Shinten and Heirinbi); Shinchiku; Choso 

 River. 



Remarks: In the year 1903, Jordan and Evermann described a 

 species of the genus Zacco from Formosa, giving the name Zacco 

 evolans. According to their statement it agrees fairly well with the 

 Japanese species, Zacco platypus, except in the much greater length of 

 the pectorals. All the characters, especially the length of the pectoral 

 fin, of the above described specimen agree quite well with those of the 

 type of Zacco evolans in the Stanford collections (No. 7129; Taihoku, 

 Formosa). But, after a close examination of a vast number of speci- 

 mens of the present species from the same locality, I found that the 

 length of the pectoral fin is variable. Even the co-type of Z. evolans 

 in the Stanford collections (No. 7333; Taihoku) is proxided with 

 shorter pectoral fins which scarcely reach to the root of the ventral. 



