FISHES OF NEW YORK 43 



Mitchill refers to its capture at Provincetown Mass. and to 

 its name of bone shark because of the peculiar structure of its 

 gills. De Kay mentions the specimen which was captured in 

 the lower harbor of New York in 1822, from which he made 

 some alterations in a drawing partly copied from Le Sueur's 

 sketch of the same fish. Storer described an individual measur- 

 ing 33 feet 3 inches. He says it is rarely observed on the coast 

 of Massachusetts. It becomes gregarious only in the breeding 

 season. 



The oil made from the liver of the basking shark was at one 

 time considered valuable. 



Order CYCLOSPONDYLI 



Suborder CYCLOSPONDYLI 



Family squalidae 

 Dogfishes 



Genus squalus (Artedi) Linnaeus 

 Body slender, elongate; mouth slightly arched, with a long, 

 straight, deep, oblique groove on each side, without labial folds; 

 teeth small, simple, equal in both jaws, their points turned aside 

 so that the inner margins form a cutting edge; spiracles well 

 developed, near the eye; gill openings moderate, all in advance 

 of pectorals; first dorsal larger than the second, far in front of 

 the ventrals, which are behind the middle of the body; second 

 dorsal behind ventrals; dorsal spines strong, not grooved; 

 caudal fin with unequal lobes, the upper elongate, broad, sub- 

 truncate at the end, the lower short and rounded; pectorals 

 large and long, placed low down; ventrals midway between end 

 of first and beginning of second dorsal. No anal fin. 



21 Squalus acanthias Linnaeus 

 S pined Dogfish 



Squalus acanthias Linnaeus, Syst. Nat. ed. X, I, 233, 1758; Joedan & Gil- 

 bert, Bull. 16, U. S. Nat. Miis. 16, 1883; Jordan & Evermann, Bull. 

 47, U. S. Nat. Mus. 54, 1896. 



Spinax acanthias De Kay, N. Y. Fauna, Fishes, 359, pi. 64, fig. 210, 1842. 



Acanthias americanus Storer, Hist. Fish. Mass. 256, pi. XXXYIII, fig. 1, 

 la, 1867. 



Acanthias vulgaris Gunther, Cat. Fish. Brit. Mus. VIII, 418, 1870. 



