1913.] NATURAL SCIENCES OF PHILADELPHIA. 531 



division of froiitals to occipital process, moderately broad. Occipital 

 process rather short and narrowly triangular. 



Gill-opening extends forwards opposite front edge of pupil. Rakers 

 about 6 + 12, slender, lanceolate, about f length of filaments, and 

 latter If in eye. Isthmus narrowly constricted, its surface largely 

 convex. Branchiostegals rather long, subequal. 



Scales moderate, well exposed in longitudinal series parallel with 

 1. 1., cycloid, and of mostly uniform size. Caudal base covered with 

 small scales. Few scales along anterior base of anal, disposed in 

 short row. Ventral with free axillary pointed scaly flap -5 length of 

 fin. L. 1. complete, decurved slightly below middle in greatest depth 

 and extending a little low along side of caudal peduncle to middle of 

 caudal base. Tubes simple, and each one extends over scale exposure 

 well anteriorly, though not nearly to its hind edge. 



Dorsal origin about midway between snout tip and hind edge of 

 adipose fin, third simple ray prolonged and filamentous and extends 

 back nearly to origin of adipose fin. Adipose fin rather large, 

 slightly less than eye in length, and inserted near last third in space 

 ])etween dorsal origin and caudal base. Caudal well forked, a little 

 longer than head, pointed lobes about equal. Anal inserted Ijehind 

 dorsal base, third simple ray longest, from which they gradually 

 diminish posteriorly, though form slight lobe in front. Pectoral 

 low, slender, pointed, reaches ventral. Latter inserted before dorsal 

 or much nearer anal than pectoral origin, and first ray produced 

 into a filament to extend back beyond front of anal. Yent close in 

 front of anal. 



Color in alcohol pale brownish generally, below paler or whitish. 

 Back with minute dusky dots, mostly arranged along edges of scales. 

 A rather narrow underlaid silvery lateral streak from shoulder to 

 caudal base. Caudal base covered with rather large dusky dots to 

 form pale dusky blotch a little larger than eye, and not reflected on 

 caudal medianly. Head dusky above, sides and below silvery to 

 whitish. Jaws pale. Iris whitish, slaty above and below. No 

 dark humeral blotch. Fins all pale or whitish. Peritoneum shows 

 through abdominal walls as pale slaty, and on preventral and post- 

 ventral region pale with rather large rounded dusky close-set dots. 



Length 40 mm. 



Type, No. 39,210, A. N. S. P. Tributary of the Madeira River 

 near Porto Velho, Brazil. January-February, 1913. Edgar A. 

 Smith. 



Also Nos. 39,211 to 39.216, paratypes, same data. Head 3^ to 



