141 



897. (6.) Acanthurus matoides. 



Acanthurus matoides, Cuv. 8f Vol. H. N. Poiss. x, p. 204 ; Day, Fish. 

 India, p. 205 (see synon.). 



D. 9/25-28. P. 17. V. 1/5. A. 3/25-28. C. 16. Vert, 9/13. 

 Length of head 4j to 5, of caudal 4|, height of body 2| in the 

 total length. Eyes diameter 3| to 3| in length of head, 2| diain. 

 from end of snout, and 1 apart. Profile from snout to dorsal fia 

 much elevated, and having a slight depression above the orbits. 

 Distance from anterior nostril to front edge of upper jaw equals 

 about of length of head ; from eye to angle of mouth | to i of 

 the same. Opercle striated. Teeth eight or nine lobate or 

 serrated incisors on either side of each jaw. Fins dorsal spines 

 of moderate strength, the last not quite so high as the first few 

 rays, and nearly g the height of the body ; the interspinous mem- 

 brane scarcely emarginate ; posterior extremity of fin and of anal 

 angularly rounded ; pectoral nearly as long as the head. Ventral 

 pointed, i as long as pectoral. Third anal spine 2 diam. of the 

 orbit in length ; rays not quite so long as those of dorsal. Caudal 

 emarginate ; in adults upwards of a foot in length the outer rays 

 become elongate. Scales rudimentary and cycloid on head, 

 shoulders, and chest, and in a band along base of dorsal fin ; 

 ctenoid and in irregular rows on the body, about 18 to 20 rows 

 between lateral line and base of last dorsal spine. Lancet-shaped 

 spine with a posterior process. Height of free portion of tail at 

 lowest part half the length of head. Colour brown, sometimes 

 \vith 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. 



Hob. Bed Sea, seas of India, Malay Archipelago, and beyond. 

 This fish is reputed to attain to 3 feet in length at Madras. 



898. (7.) Acanthurus gahm. 



Acantlmrus gahm, Cuv. fy Vol. H. N. Poiss. x, p. 219. 

 Acanthurus mata, Cuv. fy Vol. H. N. Poiss. x, p. 202; Day, Fish. 

 India, p. 205, pi. xhiii, fig. 1, Suppl. p. 789 (see synou.). 



Koli, Tarn. 



D. 9/24-27. P. 17. V. 1/5. A. 3/23-25. C. 16. 



Length of head 4|, of caudal 4|, height of body 2J in the total 

 length. Eyes diameter 3| in length of head, 2% diam. from end 

 of snout, and 1^ apart. Profile from snout to dorsal fin nearly 

 straight. Distance from anterior nostril to front edge of upper 

 jaw is not quite half the length of head, it is about the same dis- 

 tance from lower edge of eye to angle of mouth. Opercle strongly 

 striated, more strongly so and with a larger number of elevations 



