212 



PROCEEDINGS OF THE ACADEMY OF 



[Apr., 



I of filaments and latter If in eye. No pseudobranchise. Branchios- 

 tegals 5, slender. 



Body covered with smooth skin. Head smooth, and small rounded 

 fontanel close before base of occipital process. Spines smooth. 

 L. 1. slopes down from shoulder till midway along side. Axillary 

 pore moderate. 



Dorsal origin slightly nearer anal origin than snout tip, spine 

 slender, but slightly pungent, shorter than median rays and fin 

 rounded. Anal inserted about last third in space between front 

 eye edge and caudal base, fin small, and median rays longest. Adi- 

 pose fin moderate, 2| in combined head and trunk length. Caudal 

 damaged, though evidently forked. Pectoral damaged, spine with 

 lengthwise striae and not serrated. Ventral inserted about midway 



Fig. 3. — Rhamdia ortoni Fowler. (Type.) 



between snout tip and caudal base, fin Ij to anal origin. Vent 

 about opposite middle of depressed ventrals. 



Color in alcohol largely dull brownish, scarcely paler on belly and 

 lower surface. A dusky streak along side of head, extending from 

 side of snout l^ehind eye, though apparently not continued along 

 side of trunk. Fins brownish, dorsal with ill-defined dusky blotch 

 on posterior portion medianly. Iris grayish. Barbels brownish, 

 though mental ones all paler. 



Length 60 mm. (to tip of damaged caudal). 



Type, No. 21,928, A. N. S. P. Peruvian Amazon. J. Orton. 

 Presented by E. D. Cope. 



Only the above example known. It is evidently closely related 

 to Rhamdia rioja;, though differs in several characters, so that it 



