1911.] NATURAL SCIENCES OF PHILADELPHIA. 509 



Also Nos. 9 to 16, paratypes, same data. Head 3f to 4; depth 

 2f to 3f ; D. in, 9; A. usually iv, 35, frequently iv, 32, or iv, 37, 

 sometimes iv, 39; scales in 1. 1. usually 44 to 46, sometimes 43 or 

 47 + 3 or 4 more on caudal base; usually 9 scales above 1. 1. to 

 dorsal origin, seldom 8; 7 scales below 1. 1. to ventral origin; usually 

 9 scales below 1. 1. to anal origin, seldom 8 or 10; predorsal scales 

 18 to 20 usually, sometimes 17 or 21 ; snout 4 to 4 \ in head measured 

 from upper jaw tip; eye 2± to 3; maxillary 2f to 3; mandible 2\ 

 to 2|; interorbital 3 to 3-|; pectoral 1 T V to 1^; ventral If to If; 

 length 2 T 7 (T to 3f inches. 



Young examples do not differ much from the adults in appearance, 

 showing the same general coloration, though perhaps more silvery- 

 white. They are also more elongate or slender, with a larger eye, 

 and with very minute or obsolete maxillary teeth. 



This species appears to be related to Astyanax festce (Boulenger) 5 

 but differs in several respects. A. festce has: Head 4 to 4|, depth 

 2\ to 3, eye twice length of snout or 2\ to 2f in head, maxillary 

 toothless, pectoral longer than head, and 2 blackish spots at front 

 of 1. 1. 



(Na>Tos } back; ytu } half; yiovia, angle; e\do$ } appearance; with refer- 

 ence to the superficial resemblance to Notemigonus, the roach or 

 bream of the eastern United States.) 



Astyanax scierus sp. nov. Fig. 5. 



Head 3f; depth 2f; D. in, 9; A. v, 29, i; P. i, 11; V. i, 7; 

 scales 37 in 1. 1. to caudal base and 4 ? more on latter; 8 scales above 

 1. 1. to dorsal origin; 6 scales below 1. 1. to ventral origin; 8 scales 

 below 1. 1. to anal origin; 15 predorsal scales; head width l T 9 o its 

 length; head depth at occiput 1 T V; snout 3f ; eye 3f; mandible 

 2f; maxillary 2f; interorbital 2f; first branched dorsal ray If; 

 first branched anal ray 2; least depth of caudal peduncle 2-f-; lower 

 caudal lobe 1; pectoral H; ventral 2 T V 



Body elongately ovoid, well compressed, greatest depth at dorsal 

 origin, and profiles nearly alike. Predorsal edge rounded convexly, 

 also postdorsal. Preventral and postanal regions convex, post- 

 ventral trenchant, though without distinct keel. Caudal peduncle 

 well compressed, about long as least depth. 



Head moderate, well compressed, nearly flattened sides very 

 slightly constricted below, upper and lower surfaces convex, profiles 



6 Tetragonopterus festce Boulenger, Boll. Mus. Z. Anal. Corny. Torino, XIII 

 No. 329, 189S, p. 2. Rio Vinces, Ecuador. 

 34 



