FAMILY, XV— ACANTHURID^E. 207 



dorsal spine it extends over the upper half of the back, leaving an oval spot of ground colour as long as the 

 head, uncovered in the middle of the first part of its course. Just before reaching the lancet-shaped process 

 it divides into two portions, which rapidly narrow, and pass along either side of the lobes of the tail. Dorsal 

 spines orange-brown, the membrane light slate colour, having the upper edge of the fin stained with black. 

 Pectoral blackish-gray, with a large yellow oval spot on its last fourth. Anal similar to dorsal. Caudal 

 canary-yellow, which colour extends on to the free portion of the tail, as far as the lancet-shaped spine. 

 Habitat. — Seas of India to New Guinea. 



C. Setiform moveable teeth, dilated at their extremities. (Ctenodon.) 



11. Acanthurus strigosus, Plate XLVII, fig. 2. 



Acanthurus strigosus, Bennett, Zool. Journal, Fasc. xiii, p. 41 ; Cuv. and Val. x, p. 243 ; Giinther, Catal. 

 hi, p. 342 ; Bleeker, Nat. Tyds. Ned. Ind. iv, p. 264, and vi, p. 102 ; Kner, Novara Fische, p. 211. 



Acanthurus ctenodon, Cuv. and Val. x, p. 241, pi. 289 ; Giinther, Catal. iii, p. 342 ; Bleeker, Solor, 18G8, 

 p. 2 ; Klunz. Verb. z. b. Ges. Wien, 1871, p. 509. 



B. v, D. ^§3 0, P. 17, V. 1/5, A. ^! w , C. 17, L. 1. ca. 120. 



Length of head 4§- to 4f , of caudal 1/4 to 4|-, height of body 2f in the total length. Eyes — high up, 

 diameter 1/4 of length of head, nearly 2\ diameters from end of snout, and 1-g- apart. , Profile of snout very 

 gibbous. Mouth compressed so as to become angular. Teeth — setiform, moveable, having their outer third 

 dilated and spoon-shaped, with three deep clefts causing them to appear to be laterally serrated : about twenty- 

 one in the upper and twenty in the lower jaw. Fins — last dorsal spine 1/5 shorter than the longest ray, and 

 1/2 the length of the head;, soft portions of the dorsal and anal fins rather angular posteriorly. Pectoral 

 nearly as long as the head. Caudal deeply lunated. Scales — rounded, small and cycloid on the head, ctenoid 

 on the body, about nine rows between the lateral-line and the base of the last dorsal spine. Lancet- 

 shaped spine with a sharp posterior process. Free portion of the tail in its least depth equal to 2-|- in the 

 length of the head. Colours — body horizontally lineated with narrow bluish lines on a yellow ground colour, 

 the latter being somewhat the wider : numerous dull red spots about the head, more especially around 

 the eyes. Dorsal and anal fins also lineated, and a light vertical band on the middle of the caudal. 



Although the typical specimens of A. strigosus have more teeth in the lower jaw (about 25 on either side) 

 than in A. ctenodon, and one or two more rows of scales between the lateral-line and base of the last dorsal 

 spine, whilst the horizontal bands are more distinct, they appear to be otherwise the same, and only varieties of 

 one species. 



Habitat. — Red Sea, East coast of Africa, seas of India to the Malay Archipelago, and beyond : the 

 specimen figured was captured at the Andaman islands. 



D. Broad teeth fixed in the jaws, 1 to 4 dorsal spines : 5 ventral rays. (Harpurus.) 



12. Acanthurus xanthurus. 



Blyth, Fauna Ceylon, Appendix, p. 50 ; Giinther, Catal. iii, p. 343 ; Playfair, Fish. Zanzibar, p. 57, 

 pi. viii, f. 4 ; Klunz. Verb. z. b. Ges. Wien, 1871, p. 504. 



B. v, D. ^5^, P. 15, V. 1/5, A. ^i, C. 17. 



Length of head 2/9, of pectoral 1/5, height of body 2/5 of the total length. Eyes— diameter 1/4 of 

 head, 2^- diameters from end of snout, and 1± apart. Teeth — in a single row, 10 lobate incisors on either side 

 of the upper jaw. Fins — last dorsal spine longest, almost equalling the length of the longest ray, and 2/5 of 

 the height of body : dorsal rays nearly half as high as the body, the posterior end of it and of the anal rather 

 angular ; third anal spine the longest and strongest : caudal slightly emarginate. Scales — on the head very 

 rough, somewhat similar to what is seen in Batistes, those on the body are likewise rough, but in a less degree r 

 some of these roughnesses are continued on to the rays of the dorsal and anal fins, and a few between the 

 spines and rays of the former, but more at the base only of the anal fin. No posterior process to the lancet- 

 shaped spine, but two or three elevations near its base. Colours — blackish, caudal canary-yellow, head and 

 shoulders reticulated with gray : end of the pectoral stained with yellow. 



Habitat. — Red Sea, East coast of Africa, and Ceylon. Grows to at least 8 inches in length. 



13. Acanthurus velifer. 



Bloch, t. 427, f. 1 ; Bl. Schn. p. 215 ; Lacep. iv, pp. 547, 553 ; Cuv. and Val. x, p. 251 ; Riipp. Atl. 

 Fische, p. 58, t. xv, f. 2 ; Bleeker, Cocos, iv, p. 451, and Batoe, p. 315 ; Jerdon, M. J. L. and Sc. 1851, p. 138 ; 

 Giinther, Catal. iii, p. 344 ; Klunz. Verh. z. b. Ges. Wien, 1871, p. 505. 



Zabrasoma velifer, Swainson, Fishes, ii, p, 256. 



Acanthurus Ruppellii, Benn. Proc. Z. S. 1835, p. 207 ; Bleeker, Batoe, p. 316 ; Giinther, Catal. iii, 

 p. 345. 



Acanthurus Besjardinii, Bennett, 1. c. p. 127 ; Giinther, Catal. iii, p. 344. 



Acanthurus Blochii, Bennett, P. Z. S. 1835, p. 207. 



B. v, D. ^fj, P. 17, V. 1/5, A. ^„, C. 17, Vert. 9/13, Ca3c. pyl. 7. 



Length of head 1/4 to 4|, of pectoral 1/4, of caudal 1/5, height of body from 1/2 to 1/3 of the 



