FOREST, FISH AND GAME COMMISSION. 379 



A Thresher Shark was caught off the ocean beach at Water Island in May, 1899, 

 and the tail of a large example was seen near Cherry Grove, Great South Bay, on 

 August 13, 1901 ; but no specimens were taken in the bay during the summer. 



Family CARCHARIID^. Sand Sharks. 



13. Sand Shark {Carcliarias littoralis Mitchill). 



This is called Ground Shark by Mitchill and DeKay. Mitchill states that it 

 reaches the length of 8 feet. The species is rather common on our Atlantic coast, 

 especially from Cape Cod to Cape Hatteras. 



A young male taken in Gravesend Bay, June 26th, lived in captivity until 

 December 19th when the temperature of the water in which it was confined was 

 53°. Full measurements and other notes upon this specimen are published in Bul- 

 letin American Museum of Natural History, IX, 1897, pp. 329-330. 



The Sand Shark shows variation in the structure of its teeth. In a large indi- 

 vidual caught in the ocean at Southampton some of the teeth had two cusps on 

 each side of the base instead of one, the usual number. 



The last of the Sand Sharks seen by me in the fall of 1898 was observed, Sep- 

 tember 16, swimming westward near the surface near the inlet at Fire Island. 



In 1898 this shark was abundant on grassy shallows south of Toby's flat until 

 the middle of September, when it migrated westward. It preyed upon mullet, eel 

 and flat fish. On account of its habit of swimming slowly near the surface, it was 

 easily caught by spears from a row boat. 



The first Sand Shark secured in 1901 was taken in a gillnet in Clam Pond Cove, 

 Great South Bay, on July 18. Fishermen there call it the Spanish Shark. This is 

 very abundant in the bay during the summer and is a great nuisance to fishermen 

 because it destroys both fish and nets. On the evening of July 23, 1901, Clam Pond 

 Cove was overrun by the sharks so that it was almost useless to attempt gillnet 

 fishing at night. A clam fisherman killed seven of the sharks with a spear and we 

 captured several in the same way. When the sharks are intent upon feeding they 

 are easily approached in the shallow water and killed. They were usually feeding 

 upon the flat fish and the eel. 



Family LAMNID^E. Mackerel Sharks. 



14. Mackerel Shark {Isiirus dekayi Gill). 



The Mackerel Shark is described by DeKay under the name of the Mackerel 

 Porbeagle. He states that it usually reaches the length of 8 feet, but mentions an 



