mSTOEY OF THE HSHES OF MASSACHUSETTS. 223 



Carcharias vulpes, Cuv. 



The Thresher. Fox Shark. 



(PiATE XXXVI. Fig. 3.) 



Squcdus vidpes, Gmel., Lin., Syst Nat. i. pt. 3, p. 1496. 



Long-tailed Shark, Pejtn., Brit ZooL, iii. p. 110, pi. 14. 



Squalus vidpes, Fox Shark, Shaw., Gen. ZooL, v. p. 333. 



Carcharias " " " or Tkesher, Griffith's, Cuv., x. p. 599. 



Thresher, Mitch., Medical Repository, viii. p. 77. 



Sqtmlns vulpes, Thresher or Long-tailed Shark, Mitch., Trails. Lit. and Pliii. Soc. of N. Y., i. p. 482. 



" " Sea Fox or Thresher, Jenyns, Brit. Vert., p. 498. 



Carcharias vulpes, Fox Shark, Stoeee, Eeport, p. 182. 



Alopias vulpes, Sea Fox, Thresher, Sea Ape, Yabrel, Brit. Fislies, 2d edit., ii. p. 623, fig. 

 Carcharias " Thresher or Fox Shark, Linsley, Cat. of Fishes of Connecticut. 

 Carcharias vulpes, Thresher Shark, Dekay, Report, p. 348, pi. 61, fig. 199. 

 Ahpias vulpes, Stoeer, Synopsis. 



Color. All the upper part of the body, together with the fins, a dark bluish lead ; 

 beneath white. Pupils blue-black, edged with golden. 



Description. Surface of the skin rough when hand is passed toward the head. The 

 depth of the body, at the origin of the dorsal fin, is equal to a little more than one eighth 

 of the length of the fish ; the length of the tail, from its origin to its extremity, is rather 

 more than one half the entire length of the fish ; the distance from the tip of the snout 

 to the origin of the dorsal fin nearly one fifth the length of the fish. Length of the 

 head, from the tip of the snout to the first branchial aperture, nearly equal to the great- 

 est depth of the body. 



Occiput slightly convex. Eyes situated vertically, very movable in their sockets. In 

 the specimen now before me, a female, their longest diameter is one seventh the length 

 of the head ; whereas in a male specimen I formerly described, it was about one tenth the 

 length of the head. Snout blunted ; distance firom its tip to the mouth two thirds of the 

 length of the head. Gape of mouth moderate ; three rows of very small teeth in each 

 jaw, smooth on their edges ; the two first rows nearly perpendicular, the back row re- 

 curved ; teeth in the upper jaw rather the longer. Nostrils beneath, nearer the mouth 

 than the snout. Five branchial apertures placed vertically, the posterior the smallest. 



The body of this fish is terminated on the back by a slight ridge ; just back of this, is 

 a depression between it and the tail, at the origin of which is quite a concavity. 



The first dorsal fin is triangular, as long as high ; convex anteriorly, rounded above. 



The second dorsal is a mere finlet, quadrangular, with its posterior superior angle pro- 

 jecting backwards. 



