468 MITCHILL ON THE FISHES OF NEW-YORK. 



yentrals. The upper and lower caudal rajs longer than the rest ; the 

 central ones longer than those which are situated between them and the 

 lower and upper ones. 



Hindmost dorsal fin opposite the anal, and both of them broad, and the 

 distance between their expanded points eight and a half inches. 



First dorsal fin three spined. The first raj strong, long, and rough, 

 on the forepart ; the second and third not half so large. The whole 

 three connected bj a firm membrane. Thej are capable of being de- 

 pressed or let down into a deep furrow. A peculiaritj in this dorsal fin, 

 is, that when it is erected, it is kept erect bj catches in the bones and 

 soft parts within ; and that if the third raj is pressed downward, the 

 first and second are released from the catches, and descend into the fur- 

 row, without impediment. Everj beholder traces the resemblance to 

 the lock of a gun, the foremost raj being the cock, and the hindmost 

 the trigger. In the fresh specimen, the catches are four, and determine 

 the angle of the raj's elevation or descent, from about eightj degrees to 

 the horizontal line, or 0. Is said to shed his scales almost immediatelj 

 after he is taken out of water. 



Colour dove or ash, with sometimes a dull zone back of the pectoral 

 fin, and another between the dorsal and anal spreading toward the tail. 

 The skin marked out in lines decussating each other like a file. 



Ejes light brown, large, and high up toward the first dorsal. An inch 

 in front of the vent is a rough broad obtuselj serrated process ; and 

 from this to the vent, there is a row of naked spines on the carinated 

 edge. On each side of the bellj, near this carinated edge, two or three 

 rows of small rough warts or knobs. 



3. Orange file-fish. (Batistes aurantiacus.) Length between sixteen 

 and seventeen inches; depth six ; and thickness (so peculiar is its figure) 

 scarcelj more than one inch and a half. He might almost be taken for 



