UNICORN ACANTHURUS. 3^5 



more : the present species is of the same general 

 shape with the major part of the Chaetodons, being 

 of a moderately broad or deep form, tapering 

 pretty suddenly at each extremity : from the front 

 proceeds a strong, conical, horn-shaped process, 

 extending forwards nearly as far as the tip of the 

 snout, and terminating somewhat obtusely : the 

 mouth is rather small, and the teeth moderately 

 strong: the skin is somewhat rough, of a greyish 

 brown colour, and destitute of apparent scales : the 

 dorsal fin, which is rather shallow than broad, com- 

 mences almost immediately behind the head, and 

 is continued very nearly to the tail : at its origin 

 are two or three very strong spines : the anal fin 

 commences immediately beyond the breast, and 

 like the dorsal, is continued nearly to the tail, 

 which is moderately broad and of a lunated shape : 

 on each side the tail are situated two strong, but 

 short spines, rising from a very broad base : these, 

 as well as the horn in front, are much less con- 

 spicuous in the young than in the more advanced 

 specimens. 



It is a native of the Indian and Arabian seas, 

 in the latter of which it is generally seen in large 

 shoals of two or four hundred each, swimming with 

 great strength, and feeding principally on the dif- 

 ferent kinds of sea- weed. Forskal, in his Fauna 

 Arabica, tells us he was assured by a fisherman 

 that he saw an eagle (probably an Osprey) dart 

 among a shoal of these fishes, which swim pretty 

 close together, and happening to seize two at once 

 in his claws, was, in consequence of their sudden 



