FISHES OF MASSACHUSETTS. 51 



fin light, with dull patches ; the posterior short rays almost 

 concealed in a groove upon the back, when unexpanded. 



The second Dorsal is longer than high ; back of this fin are 

 eight finlets, the third and fourth of which are longest. 



The Pectoral fins arise just in front of first dorsal — of a dark 

 color above, lighter beneath ; as high again as long. 



The Ventrals commence back of pectorals ; are darker colored 

 next to abdomen. When unexpanded, these fins shut into a 

 depression, partially formed upon abdomen. 



The Anal fin arises on a line opposite the first dorsal fin let ; 

 is a little longer than high, white, with fuhginous. Back 

 of anal, seven finlets ; the posterior, smaller. Anus small, 

 directly in front of the anal fin. A thick, fleshy carina on 

 each side of the fleshy portion of tail ; on each side of posterior 

 part of this, two quite small, obtuse carinas run directly back 

 across the middle of caudal fin, causing quite a depression be- 

 tween them. 



The Caudal fin lunated, of a dirty bluish color ; length of 

 exterior rays, compared to distance between extremities when 

 expanded, as 3 to 5^, 



The fin rays are as follows : D. 20-14 ; P. 24 ; V. 6 ; A. 

 14 ; C. 24. 



XiPHiAs. Lin. 



Generic characters. Body fusiform, covered with minute 

 scales ; a single elongated dorsal fin ; ventral fins wanting ; 

 tail strongly carinated ; upper jaw elongated, forming a 

 sword ; mouth without teeth ; branchiostegous rays 7. 



X. gladius. Lin. The Sword Fish. 



Pen. British Zoology, vol. iii. 141. 



Strack's plates, 21. 1. 



Mc Murtrie's Cuv. ii. 148. 



Cuv. et Valenc. Hist Nat. des Poiss. t. viii. p. 255. 



Yarrell's British Fishes, vol. i. 143. 



