60 REPORT OF COMMISSIONERS OF INLAND FISHERIES. 



ALOPIDvE. The Thresher Sharks. 



6. Alopias VUlpeS (Gmelin). Swing-tail; Whip-tail; Thresher. 



Geog. Dist.: Abounds in all warm seas, especially in the Atlantic and 

 Mediterranean. Frequent on Pacific Coast. 



Season in R. I.: Rare in Narragansett Bay. June 25, 1908, at Quonset 

 Point, specimen 15 feet long taken in fish trap. A common shark in 

 outside waters, especially after the scup season. It is a great nuisance 

 to fishermen. At Woods Hole it is present from April until late in the 

 fall. (Smith.) 



Food: Mackerel, menhaden, herring, and other small fishes. 



Size: Sometimes as large as 300 pounds. From 4 to 20 feet long at Woods 

 Hole. 



CAHCHAMD^. The Sand Sharks. 



7. Carcharias littoralis (Mitchill). Sand Shark. 

 Geog. Dist.: Atlantic coast, Cape Cod to Cape Hatteras. 



Season in R. I.: From May to November it is common, but is less so than 



the dogfish. 

 Food: Fishes, such as flatfish, menhaden, squeteague, butter-fish, scup. 



Also crabs and squids. 

 Size: Average 4^ to 5 feet long, largest 12 feet long. 



LAMNID^. The Mackerel Sharks. 



8. Isurus dekayi (Gill). Mackerel Shark. 

 Geog. Dist. : Cape Cod to West Indies. 



Season in R. I.: Said to be more common of late years, but not abundant. 



Rare in Narragansett Bay. Taken at Tiverton and Point Judith. (U.S. 



Nat. Mus. 1887.) 

 Food: Small fishes, squids, mackerel, conger eel. 

 Size: They average 4 or 5 feet, the largest 10 feet, weighing up to 400 



pounds. 



9. Lamna cornubica (Gmelin). Bhie Shark; Mackerel Shark. 



Geog. Dist.: Newfoundland to West Indies. Common on Massachusetts 

 coast during mackerel season. In Maine, reported from off Monhegan, 

 Casco Bay, off Cape Elizabeth; in Massachusetts, from Provincetown 

 and Gloucester. 



Season in R. I.: Said by the fishermen to be more common than the mack- 

 erel shark {Isurus dekayi), but this species is probably confused with 

 others. Specimen about 9 feet long taken in trap off Quonset Point, 

 August 15, 1907. 



