522 PROCEEDINGS OF THE ACADEMY OF [Oct., 



length, and at least ^ or more in filaments, latter If in eye. Isthmus 

 broadly convex. Branchiostegals large, subequal. 



Scales moderately large, well exposed, edges entire, of mostly 

 uniform size, and disposed in series parallel with 1. 1. Striae on 

 scales concentric or obscure. Scales on caudal base slightly smaller 

 than elsewhere. Ventral with free pointed axillary scaly flap, its 

 length about 3 in fin. Front base of adipose fin scaled. L. 1. com- 

 plete, midway along side of body, very slightly curved. Tubes 

 simple, anteriorly less exposed than behind, where they reach over 

 first half of scale exposure at least. 



Dorsal origin slightly nearer snout tip than caudal base, first 

 branched ray longest, extends back beyond all of others, though fin 

 depressed back reaches a little less than half way to caudal base. 

 Adipose fin inserted slightly nearer caudal base than last dorsal ray 

 base, texture of fin somewhat ray-like above. Anal inserted slightly 

 before adipose fin origin, first branched ray longest, and depressed 

 fin reaches back | to caudal base, its lower or hind edge slightly 

 emarginate. Caudal well forked, with long slender pointed and 

 equal lobes, longer than head. Pectoral low, rather small, upper 

 rays longest, and depressed fin reaches f to ventral origin. Ventral 

 inserted a little nearer pectoral than anal origin, and depressed 

 fin reaches f to anal. Vent placed nearly opposite tips of depressed 

 ventrals or well before anal origin. 



Color in alcohol pale grayish-brown generally, lower surface scarcely 

 paler. A narrow underlaid pale slaty streak begins at shoulder 

 close over, or one scale above, 1. 1., extends concurrently with 1. 1. 

 till after dorsal fin when it falls closer, so that 1. 1. marks rest of its 

 lower boundary, and on caudal base it forms small dusky spot, 

 which rather obscure and about size of pupil. Dusky caudal spot 

 or lateral streak not reflected out on median caudal rays. At median 

 branched dorsal rays basally a dusky blotch about size of pupil. 

 No humeral blotch. Fins, otherwise than mentioned, pale grayish, 

 lower ones slightly paler. Iris deep slaty. 



Length 85 mm. 



Type, No. 39,187, A. N. S. P. Madeira River, about twenty miles 

 north of Porto Velho, Brazil. October, 1912. Edgar A. Smith. 



Only the type known. Characteristic of this species is the dark 

 spot at the base of the dorsal fin medianly, spot at caudal base 

 medianly, and the underlaid lateral streak. In these respects it 

 differs from almost all the species of the genus. 



(Ihepov, fin; <ntY!J.a^ spot; with reference to the spots on the dorsal 

 and caudal fins.) 



