FAMILY TEUTHID^ — ACANTHURUS. 139 



FAMILY XL TEUTIIID.E. 



Bodi/ cnmpirs.scd, ovale, nhlo/ig. Mouth s/iniU, not proln/clile. Tvcth. often drntatcd, and 

 disposed in a single row in both jaws. Palate and tongue smooth. A single dorsal, 

 usually long. 



Obs. This family, which is pccuHar to the warmer regions of the ocean, has been esta- 

 bhslied upon a few genera, which, at the end of the last century, did not comprise more than 

 eight or ten species. In the great work of Cuvicr and Valenciennes, now in course of publi- 

 cation, one hundred species are enumerated. It is allied to the family Scombridai, and might 

 be considered as a group subordinate to that family. The species appear to be chiefly her- 

 bivorous. I aiu not aware that we have more than one representative of this family on the 

 coast of New-York, allhough farther south we shall undoubtedly lind many others. 



GENUS ACANTHURUS. Cuvicr and Valeneien?ics. 



Teeth cutting and serrated. A movable spine on the side of the tail. Head deep, com- 

 pressed. Eyes placed high up on the head. The skin thick, and usually covered with 

 small scales. 



THE SURGEON. 



ACANTIIURI'S niLEEOTOMUS. 



PLATE LXXni. FIG. 2DI. 



Barbero. Parra, Desc. de diff. &c. p. 45, pi. 21, (ig. 2. 

 L'Acaiithure saignair. Cuv. et Val. Ilist. <Ies Poiss. Vol. 10, p. 170. 



Characteristics. Opercles deeply striated ; the scapular also striated. Bluisli brown. Tail 

 nearly even. Length (i- 12 inches. 



Description. Body elliptical and compressed. Front nearly regularly curved to the snout. 

 Mouth very small. The opercles with radiating striw, and the scapular equally so with the 

 humeral bone. Nostrils double, approximated, and the small posterior one very near the 

 orbit. Scales small, rounded, extending over all the body and head, except on the opercular 

 bones. Lateral line concurrent with, and near the dorsal outline. On each side of the tail 

 is a strong, acute, compressed, lancet-shaped spine, narrowed at the base. This lies in a 

 furrow, but can be elevated forwards at an angle of 45'', and become a powerful weapon. 

 Teeth not covered by the lips, wide, compressed, serrated on their edges ; from twelve to 

 fourteen above, and about twenty below. Branchial rays five. 



The dorsal fin compound, extending from above the branchial aperture nearly to the tail, 

 and nearly siibecpial throughout ; the first spinous ray very short. Caudal fin very slightly 

 excavated, nearly even. 



