BLUE ACANTHURUS. 377 



and is of a greyish colour, speckled on the upper 

 parts, dorsal fin, and tail, with black : the head is 

 rather large, and is formed in front into a rounded 

 protuberance immediately above the mouth which is 

 rather small and furnished in each jaw with a row 

 of numerous small teeth : the dorsal fin commences 

 at a small distance from the head, and is continued 

 nearly to the tail : at its commencement is a strong 

 spine, but the rest of the rays are soft : the anal 

 fin is placed in an opposite situation beneath, and 

 extends, like the former, almost to the tail, which 

 is moderately broad, and lunated : on each side 

 the base, at a small distance from the commence- 

 ment of the finny part, are situated two very strong, 

 slightly curved, sharp-pointed spines, in a reversed 

 direction, or with the points towards the head, as 

 in most others of the present genus. This species 

 is a native of the Indian seas, and according to 

 Cepede, was first described by Commerson, 



BLUE ACANTHURUS. 



Acanthurus Tenthis. A. ccendeus, corpore medio pallidiore, 



cauda utrinque aculeata. 

 Blue Acanthurus, with the middle of the body paler, and a 



spine on each side the tail. 

 Chaetodon caerulescens, &c. Seb. 3. f. ?>o.f. 3. 

 Teuthis Hepatus. Un. Syst. Nat. p. 507. 



Linn,eus, ill the twelfth edition of the Systema 

 Naturae, thought it necessary to arrange this fish 

 under a distinct genus among the pisces abdominales, 

 under the name of Tent his. It is however a genuine 



I 



