458 PROCEEDINGS OF THE ACADEMY OF [July, 



inches. Eye about 5 in interorbital space, A pit at origin of lower 

 caudal lobe and transverse fissure at origin of upper. Margins of dorsal 

 and caudal brownish-gray. Pectoral If in head. In most other 

 respects it agrees entirely. 



This species differs from Carcharhinus borneensis (Bleeker) in the 

 large broad pectoral. According to Bleeker's account it is 1-| in the 

 head. 



(Te^paidyjg^ ashy.) 

 2. Scoliodon acutus (Ruppell). 



Head 5f to end of last vertebra; depth about 6^ to same; depth 

 about 5 to origin of lower caudal lobe; upper caudal lobe about 2^-^ 

 in rest of body ; snout 2-^- in head ; space between tip of snout and an- 

 terior curve of mouth 2^; width of mouth at corners 3; interorbital 

 space 2^; length of pectoral along upper or outer margin If; margin 

 of pectoral posteriorly 2^; base of pectoral 3^; anterior margin of first 

 dorsal If; base of first dorsal about 1|^; posterior margin of second 

 dorsal 3f ; base of second dorsal 5f ; least depth of caudal peduncle 

 4|; anterior margin of lower caudal lobe If; base of anal 3f ; anterior 

 margin of ventral 4 ; base of ventral 4^ ; eye 4|- in interorbital space. 



Body elongate, compressed, rather slender posteriorly, and greatest 

 depth about origin of first dorsal fin. Caudal peduncle compressed, 

 rather slender, also flattened above and below. Upper surface with a 

 pronounced median groove and a transverse slit-like pit at origin of 

 upper caudal lobe. Lower surface shallowly concave medianly, and 

 also with a small pit at origin of lower lobe. Depression along middle 

 of back 'between dorsals very slight. 



Head rather slender, depressed, its greatest width about If in its 

 length, and upper surface convex. Snout rather angular, depressed, 

 and rising up more convexly posteriorly. Eye small, circular, and 

 position a trifle anterior. Nictitating membrane well developed. 

 Symphysis of mandible about opposite front rim of orbit. Mandible 

 rather long, similar to shape of snout. Teeth oblique, slender, sharp 

 pointed, entire, and those in upper jaw directed posteriorly, also with 

 a notch on outer or posterior margin. Lower teeth a little more slender 

 than upper. Tongue broad, flat, and little free except around edges. 

 Each corner of mouth with a short groove running along outer margin 

 of upper jaw. Nostrils nearer front of mouth or orbit than tip of snout, 

 a little oblique, and each with a small pointed flap. Interorbital space 

 broad and convex. 



Gill-openings 5, last two above base of pectoral, and median three 

 largest. No spiracle. 



