80 Annals of the Carnegie Museum. 



eighteen predorsal scales, not forming a distinct median series; occipital 

 process short, extending about one-eighth the distance to the dorsal; 

 fontanels large, the anterior very sharp-pointed in front, as long as the 

 parietal. 



Mouth very large and very oblique, the preorbital very narrow; 

 maxillary-premaxillary border equal to the length of the head without 

 the opercle; maxillary very slender, reaching to below the middle of 

 the eye, nearly to the angle of the mandible; suborbitals covering the 

 entire cheek, preopercle very narrow, gill-membranes free from each 

 other and from the isthmus. Gill-rakers about 2 -f 7; origin of dorsal 

 equidistant from eye and end of the lateral line; dorsal pointed, about 

 equal to the head; adipose well-developed; caudal forked, the lobes a 

 little shorter than the head; origin of anal about equidistant from tip 

 of snout and end of lateral line; height of anal lobe about equal to 

 head without opercle; ventrals small, reaching anal; pectorals very 

 large, reaching the anal, with seventeen rays. 



Caudal naked, a few scales in a single row along the bases of the 

 anterior anal rays; a small axillary scale. Scales thin, without radial 

 striae, everywhere regularly imbricate; lateral line indicated on about 

 five scales. 



5. Stethaprion crenatus sp. no v. (Plate XVI.) 



5228 a-c, C. M. Type (c) 95 mm., paratypes 53 and 85 mm. San 



Joaquin, Bolivia, September 4, 1909. Haseman. 

 5756 a, C. IVI. Paratype 96 mm., Cachoele de Riberao de Rio Madeira, 



October 17, 1909. Haseman. 



Head 4; depth 1.5 in largest, 1.75 in smallest; D. 12; A. 3 + 42 or 43; 

 scales 21 to 23-66 or 67-16 or 17; eye. 3 in head, interorbital 2-2.33. 



Much compressed; dorsal profile steep to the dorsal, depressed over 

 the eyes; ventral profile a nearly perfect segment of a circle from the 

 gill-opening to the end of the anal; predorsal line scaled, but without 

 a regular median series of scales; about five series of narrow scales 

 ending in spines along the ventral edge, the scales on either side of 

 these not quite symmetric; occipital process extending one-third of 

 the distance to the dorsal; frontal fontanel oval, considerably shorter 

 than the parietal, its anterior margin over front of pupil; a naked area 

 about a fourth as wide as the second suborbital at its widest point, 

 extending around its entire free margin; maxillary-premaxillary border 

 longer than eye; premaxillary with four teeth in the outer series, five 



