]919.] 



NATURAL SCIENCES OF PHILADELPHIA. 



13 



Mouth small, with short inclined gape, and mandible slightly 

 protruded beyond snout tip. Teeth small, simple, conic, and 

 as very narrow band or row along front edges of trenchant jaws. 

 Mouth roof toothless. Maxillary well exposed, or at least lower 

 half its Avhole length, extends slightly beyond front of eye or not 

 quite half way in iris to pupil. Tongue smooth, depressed, mod- 

 erately long, front end rounded and free. Nasal cavity close 

 before eye, about half of pupil. Preorbital rather slender, 1| 

 in eye. Interorbital broad, slightly concave. 



Fig. 4. — Cypselurus hyperisiius. 



Gill-opening extends forward to front eye edge. Gill-rakers 

 7-f-17, lanceolate, about long as filaments, which slightly less 

 than 2 in eye. Isthmus long slender frenum in front. 



Scales large, mostly adherent, cycloid, moderately exposed, 

 largest anteriorly on back and head above, basal radii 3 to 5, 

 circuli complete, about 26 to 30. Dorsal and anal apparently 

 scaleless, though caudal base scaly. Head covered with scales, 

 2 or 3 rows on cheek and edge of snout rather broadly naked. 

 Breast scales of moderate size. Lateral line apparently not beyond 

 anal as squaination damaged. 



Dorsal origin at last third between hind pupil edge and caudal 

 base, front rays a little elevated. Anal origin slightly before 

 that of dorsal, fin similar. Caudal well forked, lobes pointed 

 and lower much longer or about equals head and eye length. Pec- 

 toral long, reaches back not quite far as last depressed dorsal 

 and anal rays, thus not quite to caudal base, and first or upper- 

 most simple ray connected with next or first branched ray by 

 broad membrane. Ventral inserted midway between hind eye 



