30 



Family ALOPECIID^I. 



172. Alopias vulpes (Linn.} Bon. SWINGLE-TAIL, THRASHER 

 SHARK. Carcharias vulpes Storer, Hist. Fish. Mass., 1867, p. 245, pi. 

 xxxvi, fig. 3. Several "Swingle-tails," have been taken within the 

 past ten years, between Boston and Gloucester. 



Family SPHYRNID^E. 



173. Sphyrna zygaena (Linn.) Mull. & Henle. HAMMER-HEAD 

 SHARK. Zygaena malleus Storer, Hist. Fish. Mass., 1867, p. 262, pi. 

 xxxviii, fig. 3. According to Captain Atwood, the hammer-head is 

 "seldom seen" at Provincetown. 



174. Eulamia obscura (LeSueur}. DUSKY SHARK. " A "blue 

 shark" is recognized by the fishermen of Massachusetts Bay, which 

 is probably either this species or E. Milberti. 



Family GALEOEHINID^J. 



175. "Prionodon lamia" Putnam. Bull. Essex Inst., vi, 1874, 

 p. 72. This species was provisionally identified by Prof. Putnam 

 from a tooth obtained on St. Peter's Bank belonging to a fish esti- 

 mated to have been at least thirteen feet in length. 



176. Mustelus canis (Mitch.) DeKay. SMOOTH DOG-FISH. Mus- 

 telus canis Storer, Hist. Fish. Mass., 1867, p. 251, pi. xxxvii, figs. 2, 2a. 

 This species is not unusual about Provincetown in summer, and is 

 occasionally taken in other parts of the bay. The Essex Institute 

 has young specimens taken off the Central wharf, Salem, in 1856. 



Family SPINACIDJE; 



177. Squalus acanthias Linn. DOG-FISH. Acanthias ameri- 

 canus Storer, Hist. Fish. Mass., 1867, p. 256, pi. xxxviii, fig. 1, la. 

 Common everywhere in summer, coming up on the fishing .grounds in 

 immense schools and very annoying to fishermen. 



178. Centroscyllium Pabricii (Rein.) Mull. & Henle. GREEN- 

 LAND DOG-FISH. Centroscyllium fabricii, Giinther, Cat. Fish. Brit. 

 Mus., viii, 1870, p. 425. Common on the off-shore banks in company 

 with Centroscymnus. 



179. Centroscymnus coelolepis Bocage & Capello. BLACK 

 DOG-FISH. Centrophorus coelolepis Giinther, Catalogue Fish. Brit. 

 Mus., viii, 1870, p. 423. This species is abundant on the off-shore 

 banks, at the depth of 200 fathoms and more. It is ovoviviparous 

 like Squalus. 



