120 THE PLAGIOSTOMIA. 



Hypoprion. 



Hypoprion Muller & Hbnle, 1841, Plagios., p. 34. 

 Hypoprionodon Gill, 1861, Ann. N. Y. lye, 7, p. 399. 



Hardly distinct from species of Carcharinus in which the lower teeth are 

 erect and smooth on the edges, and the bases only of the upper teeth are serrated. 

 Indian Ocean and Archipelago; West Indies. Fossil in the Miocene. 



Second dorsal larger than anal, and origin little farther back 

 snout short, broad 



origin of first dorsal about midway from snout to caudal pit 



brevirostris (page 120) 

 Second dorsal smaller than anal and origin above hinder third of its base 

 snout elongate, pointed 



origin of first dorsal above inner angle of pectoral macloti (page 121) 

 Second dorsal smaller than anal, origin little behind that of anal 

 snout moderate, shorter than that of H. macloti 



origin of first dorsal close behind the pectoral hemiodon (page 122) 

 Second dorsal and anal equal and opposed 

 snout broad and broadly rounded 



first dorsal nearer to bases of pectorals than to ventrals 



playfairii (page 122) 

 snout elongate, sharp 



first dorsal j length of base farther back than pectorals 



signatus (page 122) 



Hypoprion brevirostris. 



Hypoprion brevirostris Poey, 1868, Repertorio, 2, p. 451, pi. 4, f. 5, 6, 20; 1876, An. Soc. Esp. hist, nat., 

 5, p. 198; Jordan & Gilbert, 1882, Proc. U. S. nat. mus., 5, p. 581; 1883, Bull. 16, U. 8. nat. 

 nnis., p. 61; Jord. & Everm., 1896, Bull. 47, U. S. nat. mus., p. 41. 



Carcharias {Hypoprion) brevirostris Gunth., 1870, Cat. fishes Brit, mus., 8, p. 362. 



Carcharias brevirostris Jordan, 1884, Proc. U. S. nat. mus., 7, p. 104. 



Body rather stout, compressed; head large, depressed; snout short, broad, 

 blunt; nostrils behind the middle of the preoral length, valves with a sharp lobe. 

 Mouth with a short fold at the angle. Teeth broad-based, two-rooted, narrow- 

 cusped, in T\—zz — rows; upper with triangular, unserrated cusps rising from 

 serrated shoulders on the base; lower with somewhat narrower cusps on bases 

 without serrations. The only serrations on the teeth of this species are those on 

 the basal processes of the upper series. In three rows at the symphysis the teeth 

 are smaller, those in the median rows are very small. Gill clefts wide. Eye 



