N)>iaes. point (.'J and huplantcd like tee£h (24 on each side). 

 The mouth is uuder the head, and contains the true teeth, 

 which are small and rounded. This fisii unites to the elong- 

 ated form of. the sharks a body, flat in front, and gills, pierced 

 3>cueath, as in the Hays or Skates. The skin is finely sha- 

 greened. Dusky above, pale grey beneath. Length 12 to 

 ir> feet, including the .siiw. 



P. ant iguo rum, Lathiuu, Trans. Linn. Soc. 171M, II. p. 

 277, pi. 2(>, fig. 1. 



Oceur.s in the ocean ofi' our coast, but occa^sionally enter.s 

 y 'hesapoake Bay. 



Ac.Ai*. (.V>iJ.. 



LXVII— LAMNIBff;. 



CAUCIIARODON, Muller ,S: Henlc 



C atwoodi. 



The Man-Eater. 



Body very short anterior to tiie ventral fins. Pectorals 

 large. Anal back of second dorsal. Teeth in both jaws, 

 triangular, serrated; those of the lower jaw the smaller. 

 About twenty-four teeth in each row. Above leaden grey; 

 white beneath. Nearly U> feet in lengtii. 



Carcharias' af.woodi, Htorer. Proc. Bost. S(»c. Nat. Pli.st. 

 Ill, 1B48, p. 71. 



Oarchorodon afivooill, (lill, Proc. Ac. NTat. 8c. Pliilad. 

 ]S(;4, p. 2G(). 



i'iUter.s (*hcsa[)eake Bay and roams over its entire length. 

 It proceeds sometimes as far as to tin; outer harbor of Balti- 

 more, and is g(^nerallv the terror of bathers in the I'atapsco 

 Bivcr. 



LXVIII-ALOPECIIDa:. 



Al.OPTAS, Mulj. & llenle. 



A. vulpes. 



Thresher Shark. 



l>o(iy cylindrical, tiiickest before the dorsal iin. with a 

 ridge on its U{)j>er surface towards the tail, and a deep cavity 

 at tlie base of caudal fin. l>ack regularly arched from above 

 the j)ectoi"als to the end of the snout, wliich is blunt. »Skin 

 roughened with n.iinute prickles, which arc directed back- 

 wards, and olu'ious to the toucii. Mouth in shape of a horse~ 

 shoe, with r'iircc rows of distajit, fiat-, triangular, smo,)tb.- 

 1 4 



