HEXANCHUS CORINUS. 17 



cusps, hindmost teeth small, with cusps much reduced. Lower jaws with a 

 median tooth which is without or with a median cusp. Agassiz and Dumeril 

 have no median cusp in their figures, while Bonaparte and Moreau both figure 

 it as present; in the specimen at hand there is no median lower tooth. First 

 lateral teeth of the lower jaw with seven cusps; primary cusp little longer, 

 without serrations on its inner edge; other cusps and teeth decreasing in size 

 regularly, and cusps increasing in number, one or more, backward. 



Dorsal moderate, origin above ends of bases of ventrals, hinder angle acute. 

 Anal smaller, origin below middle of base of dorsal, middle of base below end of 

 that of dorsal, fin acute-angled behind, base about one length distant from origin 

 of subcaudal. Caudal long, one third or more of the total, with modified scales 

 along its upper edge; subcaudal deep anteriorly, separated from the tip by a 

 notch. Pectorals large, as broad as long, subtruncate. Ventrals rather longer 

 than the dorsal, three times as long as broad, hind margin very oblique, outer 

 angle rounded. 



Uniform dark brownish. 



Described from a 33 inch specimen, taken at Nice, France, which exhibits 

 no traces of symphyseal teeth on the lower jaws. Regan, 1905, identifies this 

 species from Japan, which appears to be correct; he also identifies H. corinus 

 from California as the same species, which is not quite so satisfactory. 



Hexanchus corinus. 



Hexanchus corinus Jordan & Gilbert, 18S0, Proc. U. S. nat. mus., 3, 352; 1S83, Bull. 16, U. S. nnt. 



mus., p. 62; Jord. & Everm., 1896, Bull. 47, U. S. nat. mus., p. 18. 

 Notidanus vulgaris Perez, 1886, Estud., p. 8; Philippi, 1887, Ann. Univ. Chile, 71 , p. 22, pi. 41, f. 1. 



Head large, broad, depressed; snout short, blunt. Nostrils near the end 

 of the snout. A groove at the angle of the mouth reaching halfway to the gill 

 opening. Eyes large, two thirds the length of the snout. Spiracles small, far 

 behind the eyes. Six gill openings. No median tooth in the upper jaw, anterior 

 teeth slender, sharp, without basal cusps; the anterior of the lateral teeth is 

 larger, has a single cusp at the outer side of its base and is without denticles on 

 its inner edge; backward the number of denticles on the outer side of the base 

 and on the inner edge increase, thus approaching the forms of the teeth of the 

 lower series. Median tooth of lower jaw small, with a median cusp and three 

 cusps at each side the inner of which is the larger; the first of the lateral teeth 

 like the second to the fifth has six cusps, the inner of which is largest and finely 

 serrated and the others decrease gradually in size outward; sixth and seventh 

 of these teeth somewhat smaller. 



