FAMILY, XV— ACAJSTTHURID^. 205 



Fins — last dorsal spine nearly 1/3 the height of the body, and about equal to the rays : posterior extremity of the 

 soft dorsal and anal rather angular. Pectoral as long as the head. Caudal emarginate. Scales — about fourteen 

 rows between the lateral-line and the base of the last dorsal spine. A posterior process to the lancet-shaped 

 spine. Colours — brown, caudal with a broad white posterior edge, having a dark base behind it. The skin in the 

 British Museum has a dark ring on the shoulder, considered normal, but which appears very like an ink mark : 

 the pectoral seems to have been tinged with yellow in its posterior half on the lower side. 

 Habitat. — An immature specimen from Ceylon in the British Museum. 



6. Acanthurus matoides. 



Chcetodon nigrofuscus, Forsk. p. 64. 



? Chcetodon nigricans, Grmel. Linn. p. 1245. 



Acanthurus nigricans, Bl. Schn. p. 211 (pt.). 



? Acanthurus rasi, Cuv. and Val. x, p. 203. 



Acanthurus matoides, Cuv. and Val. x, p. 204 ; Bleeker, Tenth, p. 12 ; Giinther, Catal. iii, p. 330 ; Day, 

 Fish. Malabar, p. 126 ; ? Kner, Novara Fische, p. 210 ; Playfair, P. Z. Soc. 1867, p. 858 ; Klunz. Verh. z. b. Ges. 

 Wien, 1871, p. 508. 



Acanthurus annularis, Cuv. and Val. x, p. 209 (with a whitish basal caudal band). 



Acanthurus nigrofuscus, Cuv. and Val. x, p. 214 (not Giinther, Catal.). 



Acanthurus xanthopterus, Cantor, Catal. p. 206, pi. iv. 



Ehombotides matoides, Bleeker, Sanger, 1868, p. 1. 



B. v, D. „?„, P. 17, V. 1/5, A. ^^, C. 16, Vert. 9/13. 



Length of head 4-|- to 1/5, of caudal 4s\, height of body 2-J in the total length. Eyes — diameter 3§ 

 to 3| in the length of head, 2| diameters from end of snout, and 1 apart. Profile from snout to dorsal fin much 

 elevated, and having a slight depression above the orbits. The distance from the anterior nostril to the front 

 edge of the upper jaw equals about 2/3 of the length of the head : from the eye to the angle of the mouth 2/3 

 to 3/5 of the length of the head. Opercle striated. Teeth — eight or nine lobate or serrated incisors on either 

 side of the upper jaw, and the same in the lower. Fins — dorsal spines of moderate strength, the last not quite 

 so high as the first few rays, and equal to nearly 1/3 the height of the body : the interspinous membrane scarcely 

 emarginate : the posterior extremity of the fin and also of the anal angularly rounded : pectoral nearly as long 

 as the head. Ventral pointed, 4/5 as long as the pectoral. Third anal spine equals 2 diameters of the orbit in 

 length : rays not quite so long as those of the dorsal. Caudal emarginate : in the adult as upwards of a foot in 

 length its outer rays become elongated causing the fin to be deeply lunated in its last half. Scales — rudi- 

 mentary and cycloid on head and over shoulders, chest, and in a band along the base of the dorsal fin : 

 ctenoid, and in irregular rows on the body, about 18 to 20 rows between the lateral-line and base of the last 

 dorsal spine. Lancet-shaped spine with a posterior process. Free portion of the tail at its lowest part equal 

 to 1/2 the length of the head. Colours — brown, sometimes with narrow light bands across the cheeks and along 

 the body •_ lips black : dorsal and anal fins with several longitudinal bands : caudal with a white band across its 

 base, sometimes the rest of the fin is light-coloured with a crescentic dark mark at its posterior extremity. 

 Outer half of pectoral yellowish-green. 



Habitat. — Red Sea, seas of India to the Malay Archipelago and beyond. It is reputed to attain to 

 3 feet in length at Madras. The largest obtained by me was 22-|- inches long. It is said to be good eating but 

 not brought to the tables of Europeans. 



1. Acanthurus mata, Plate XLVIII, fig. 1. 



Chcetodon nigrofuscus ?, Russell, i, p. 64, and Mata, pi. 82 (not C. nigrofuscus, Forsk.). 



Acanthurus mata, Cuv. and Val. x, p. 202 ; Bleeker, Java, ii, p. 432. 



Acanthurus rasi, Jerdon, M. J. L. and Sc. 1851, p. 138 (not Cuv. and Val.). 



Acanthurus Bleeheri, Giinther, Catal. iii, p. 331 ; Klunz. Verh. z. b. Ges. Wien, 1871, p. 509. 



Koli, Tarn. 



B. v, D. ^_Vt, P. 17, V. 1/5, A. T fy r , C. 16. 



Length of head 4f , of caudal 4f , height of body 2| in the total length. Eyes — diameter 3| in length 

 of head, 2j diameters from end of snout, and 1J apart. Profile from snout to dorsal fin nearly straight. The 

 distance from the anterior nostril to the front edge of the upper jaw equals not quite 1/2 the length of the head, 

 whilst it is about the same distance from the lower edge of the eye to the angle of the mouth. Opercle strongly 

 striated, more strongly so and with a larger number of elevations than in A. matoides. Teeth — eight or nine 

 incisors in the upper jaw serrated along 3/4 of their external edge, and the same in the lower. Fins — dorsal 

 spines increase in length to the last which is nearly or as high as the anterior rays and equals 1/3 in that of the 

 body : the interspinous membrane scarcely emarginate ; the posterior portion of the' fin and also of the anal 

 angularly rounded. Pectoral as long as the head. Third anal spine equal to about If diameters of the orbit 

 and the rays similar to those of the soft dorsal. Caudal emarginate, upper lobe the longer. Scales — rudimentary 

 on head and over the nape, becoming ctenoid and in angular rows on the body, there appear to be about 150 to 

 160 rows descending to the lateral-line : and about 16 or 18 rows between the lateral-line and base of the last 

 dorsal spine. Lancet-shaped spine on the side of the free portion of the tail with a posterior process. Colours — 

 blackish-brown : lips and fins black. 



