1906.] NATURAL SCIENCES OF PHILADELPHIA, 315 



Isthmus a little narrowly compressed. Branchiostegals 4, large and 

 subequal. 



Scales mostly fallen, little rough, apparently disposed in even longi- 

 tudinal series parallel with lateral line, each one with one or more 

 striae, and apparently of more or less even size. Small scales appa- 

 rently along bases of dorsal and anal, and on that of caudal. No trace 

 of ventral flap remains. Predorsal region keeled. Postdorsal region 

 rounded. Upper and lower surfaces of caudal peduncle, preventral 

 and postventral regions keeled. Lateral line (damaged) continuous, 

 on base of caudal, nearly straight, more or less median, and of simple 

 tubes. 



Origin of dorsal about midway between tip of snout and base of 

 adipose fin, first branched ray longest, and others apparently gradu- 

 ated down. Adipose fin wnth base over those of last anal rays. Origin 

 of anal much nearer base of caudal than origin of ventral, or nearly 

 midway between base of last dorsal ray and that of caudal, and anterior 

 rays apparently longest. Pectoral low, rather long, and reaching 

 ventral. Ventral with origin a trifle in advance of middle of base of 

 dorsal, and reaching nearly | of space to anal. Vent close in front of 

 anal. 



Color in alcohol pale plumbeous, sides and lower surface more or less 

 silvered, and back dusky-plumbeous. Upper siu-face of head dusky- 

 plumbeous, sides and lower surface silvered. Fins all pale brownish. 

 Dorsal with four well-defined broad deep brown cross-bands. Caudal 

 with two similar colored oblique bands on each lobe, and a median or 

 horizontal one from base of fin to tips of middle rays. Anal with lower 

 anterior tip of fin brownish, and another horizontal transverse band 

 from origin of fin to tips of more posterior rays also of brownish. 

 Pectoral and ventral apparently plain pale brownish. Iris dull 

 brownish. 



Length 2{ inches. 



Type, No. 8,033, A. N. S. P. .Ajiibyiacu River, Equador. John 

 Hauxwell. Only one example. 



Formerly identified by Cope with Prochilodus insignis Kner, this 

 species may at least provisionally be regarded as distinct. This is in 

 view of the identity of Prochilodus insignis Jardine and P. insignis of 

 Kner, and later of Dr. Glinther, not yet having been proved. Schom- 

 burgk's figure, as presented by Jardine, shows each lobe of the caudal 

 with five oblique bands besides the median one, which is also in agree- 

 ment in the description. Dr. Giinther's Amazon examples are said to 

 have only three or four bands across each lobe besides the median one. 



