Tail truncated, spine on the side of the tail very distinct, imbedded in a sheath.
Pectoral fin, fifteen rays, first very short: Ventral fin, five rays, one very strong, short.

Dorsal fin, thirty-one; anterior very strong, first short.

Anal fin, twenty-three; two first very strong and short.

Caudal fin, sixteen rays, divided.
Body 3; tail 1 1/4 inches long.

Body 2 3/4 high; dorsal fin 3/4; pectoral fin 1 1/4 inches long.
This fish belongs to the Genus Acanthurus of Bloch, adopted by Shaw (Harpurus, of Forster) but as that genus is apparently formed from the type of Linnaeus' Genus, Teuthis, I have adopted the latter name for those Chetodons which have one spine on each side of the tail, and Acanthurus for those that have two.