510 



PROCEEDINGS OF THE ACADEMY OF 



[Sept., 



similarly inclined and both a little convex. Snout short, convex 

 over surface and in profile, length about f its basal width. Eye 

 circular, a little elevated, and its centre about first | in head. Eye- 

 lids narrow, thin. Pupil circular. Maxillary vertically inclined, 

 narrow, with greatest expansion about 3| in eye, extends back a 

 little behind front eye edge, though not to front pupil edge. Upper 

 lip firm, tough, lower thick, fleshy and free in front. Mouth rather 

 small, short, commissure nearly horizontal, and powerful jaws with 

 lower not protruding when closed. Premaxillary teeth biserial, 

 anterior a little smaller and tricuspid, and posterior quincuspid 

 and broad. All premaxillary teeth with convex surfaces, median 



Fig. 5. — Astyanax scierus Fowler. Type. 



cusp much largest, and edges of all denticles entire. Two small 

 teeth on lower edge of each maxillary inside mouth. Mandibular 

 teeth uniserial, symphyseal pair enlarged, quincuspid, others, of 

 which 3 follow graduated slightly back on each ramus, similar. 

 Mandibular dentition extends about half way on each ramus. No 

 other teeth. Upper and lower buccal folds broad, especially former. 

 Tongue a little long, depressed, rounded and not free in front. Man- 

 dible strong, convex over surface, and rami moderately elevated 

 inside mouth. Nostrils together, close before upper front edge of 

 eye, anterior simple pore and posterior exposed in crescent. Inter- 

 orbital evenly convex. Preorbital narrow, similar to maxillary, 

 and latter mostly slipping below its lower edge. Infraorbital 



