Si'ARKs: IcH rnvoi.oGiCAi. Survey ai«iut San Juan Islands. 163 



The spccinu'iis arc (lci)()siU'(l in tlic cdlliTlions of Stanford University, 

 in the Carnegie Museum, and in the American Museum of Natural 

 History. The tyi^es of the new species are in the Carnegie Museum. 



Family HEXAXCHID/E. 

 I. Hexanchus griseus (Gmelin). 



A large specimen of this species was taken in the Irawl b\- the col- 

 lectors of the Puget Sound Marine Station near Anocortes in 1908. 



In a "Note on Hexanchus griseus'' (Ann. and Mag. Nat. Hist. 

 (7), X\T, 1905) Mr. C. Tate Regan in comparing specimens of this 

 genus from the Atlantic and Japan with a small one from the Pacific 

 Coast of the United States {Hexanchus corinus Jordan and Gilbert) 

 concluded them to be all of the same species. 



The species Hexanchus corinus was based on the following characters 

 in the original description. "This species is closely related to Hex- 

 anchus griseus, from the Mediterranean and Eastern Atlantic [also 

 from the West Indies]. It difTers chiefly in the form of the teeth of 

 the lower jaw, which are serrated on the inner edge, and have on the 

 upper or outer edge only six cusps instead of eight or nine." The 

 largest of the two typical specimens was forty-three inches in length. 



Dr. Jordan recently obtained in the market at San Francisco the 

 head of a specimen of this shark. The animal was six or seven feet 

 in length. The jaws were saved. The teeth of this specimen tend 

 to prove the correctness of Mr. Regan's conclusions, as each tooth 

 of the lower jaw has nine well developed cusps. 



As to the serrations on the inner edge of the lower teeth Miiller 

 and Henle (Syst. Besch. d. Plagiostomen, p. 81) say of Atlantic 

 specimens "Der innere Rand sehr fein gezahnelt." 



Since the above was written a female specimen sixty-seven inches 

 in entire length was received from a market in San Francisco. Its 

 description is here included. 



Body robust; moderately tapering backwards; the caudal not much 

 bent upwards. Head, measured obliquely across top from tip of 

 snout to first gill opening. 4.16 in length of body to base of caudal, 

 or twice the length of the caudal. Length of eye equal to half the 

 distance from upper lip to tip of snout, which distance is contained 

 3.66 times in head (obliquely across top). Nostrils near outer edge 

 of snout; a line drawn between posterior edges of nostrils across snout 

 falls medially a little nearer upper lij) than tip of snout. Distance 



