112 ACANTHOPTERYGII. 



A. Scales small. 

 1. Holacanthus imperator, Plate XXVIII, fig. 5. 



Chmtodon imperator, Bloch, p. 1164, t. 194; Gmel. Linn. p. 1255 ; Bl. Schn. p. 217. 



Holacanthus imperator, Lacep. iv, pp. 527, 534, pi. 12, f. 3 ; Cuv. and Val. vii, p. 180 ; Bleeker, Celebes, 

 iii, p. 758, and Act. Soc. Neder. i, Man. en Makass. p. 49 ; Giinther, Catal. ii, p. 52, and Fische d. Sudsee, p. 53, 

 t. xli, fig. A ; Klunz. Verh. z. b. Ges. Wien, 1870, p. 787. 



B. vi, D. ^_fe, P. 21, V. 1/5, A. ^^, C. 17. 



Length of bead 1/4 to 3/13, of caudal 1/7, height of body 1/2 to 4/7 of the total length. Eyes — diameter 

 1/3 to 1/4 of the length of head, lj to 1-| diameters from the end of snout, and 1 apart. Body oval, strongly 

 compressed : snout elevated. The maxilla reaches half-way to below the front edge of the orbit. Vertical linib 

 of preopercle rather oblique and serrated, as is also its horizontal limb ; angle with a strong, smooth, curved 

 spine, one and a quarter diameters of the orbit in length, and reaching to below the base of the pectoral fin. 

 Teeth — in closely set rows, some of them with a small lobe on either side of their base. Fins — dorsal spines 

 strong, gradually increasing in length, with the interspinous membrane deeply notched, its soft portion as well 

 as that of the anal rounded. Pectoral as long as the head behind the angle of the mouth : ventral reaching to 

 the anal : anal spines strong, the third the longest and equal to the last of the dorsal or the head excluding the 

 snout : caudal rounded. Scales — small, covering the vertical fins. Colours — Body blue, having a greenish 

 tinge along the back : about nineteen canary-coloured lines pass upwards to the dorsal, horizontally to the 

 caudal, or downwards towards the anal fin. A large black descending band with a blue anterior edge, on the 

 shoulder : chest chestnut. A light blue stripe across the snout, round the cheeks, and to the preopercular spine, 

 which is nearly black. A brown band superiorly edged with blue crosses the eye and passes on to the pre- 

 opercle. Opercle yellow, edged with blue, and the branchiostegals black. A narrow black edge to the caudal : 

 ventral dark with orange coloured rays : pectoral blackish. 



A coloured drawing nearly 8 inches in length, labelled Kulloo holi meen and Holacanthus imperator, exists 

 amongst Sir Walter Elliot's figures of fish. 



Habitat. — Prom the East coast of Africa through the seas of India to the Malay Archipelago. 



2. Holacanthus Nicobariensis, Plate XXVIII, fig. 6 (variety semicirculatus). 



Ghcetodon Nicobarcensis, Bl. Schn. p. 219, t. 50. 



Holacanthus geometricus, Lacep. iv, pp. 528, 537, pi. xiii, fig. 1 ; Cuv. and Val. vii, p. 189. 



Holacanthus striatus, Biippell, N. W. Fische, p. 32, t. x, f. 2 ; Bleeker, Amb. iv, p. 414 ; Giinther, Catal. ii, 

 p. 53. 



Holacanthus semicirculatus, Cuv. and Val. vii, p. 191, pi. 183 ; Bleeker, Amb. vi, p. 414 and Banka, p. 452 ; 

 Voy. Coq. Zool. Poiss^ p. 173, pi. xxx, fig. 3; Giinther, Catal. ii, p. 53. 



Holacantlms Nicobariensis, Bleeker, Amb, vi, p. 413 ; Giinther, Catal. ii, p. 52 and Fische d. Sudsee, 

 p. 54, t. xli, f. B. 



B. vi, D. 'H*, P. 19, V. 1/5, A. T1 fi rT , C. 18, L. r. ffif^. 



Length of head 1/4, of pectoral 1/4, height of body 1/2 to 4/9 of the total length. Eyes — diameter 1/3 to 

 2/7 of length of head, 1 diameter from end of snout, and 3/4 to 1 diameter apart. Preopercle serrated, its spine 

 smooth reaching to opposite the posterior edge of the opercle and equal in length to 3/4 or 1 diameter of the orbit. 

 Teeth — brush-like. Fins — dorsal spines shorter than the rays, the soft dorsal angularly-rounded in the adult : 

 caudal rounded. Scales — minute, about thirteen rows between lateral-line and base of sixth dorsal spine. 

 Colours — this fish shows different distributions of the same colours, some dependant on age, others not so. In 

 the young (H. striatus') it is deep blue with slightly curved vertical bands, alternately white and bluish- white, 

 the white ones being the broader. Caudal white, with or without a narrow black outer margin. In a specimen 

 in my collection there are reticulated blue lines between the broad white band behind the eye and on one 

 descending from the centre of the spinous dorsal. In the adult (H. semicirculatus) the vertical bands have a 

 more curved direction, the convexity being forwards. In the Nicobariensis this is still more apparent, a white 

 spot or short transverse band being the centre around which the body bands are curved. In both these last 

 varieties the tail fin is coloured. 



In my H. striatus 2-fL inches in length, the preopercular spines are bifurcated at their extremities, in a 

 specimen in the British Museum (l^ inches) they are not so. 



Klunzinger, Verb. z. b. Ges. Wien, 1870, p. 789, enumerates Holacanthus striatus, Riipp. Blkr. &c, 

 H. lineatus, Riipp. H. ccerulescens, Riipp. Chwtodon asfur, var. b. Forsk. Holacanthus haddaja, C.V., Chmtodon 

 maculosus, T?orsk.=Holacanthus maculosus, Holacanthus aruset, Lacep., Fomacanthus asfur, Lacep. as varieties 

 of Chcetodon asfur, T?orsk.=Holacanthus asfur. 



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



3. Holacanthus annularis, Plate XXIX, fig. 1. 



Cliaitodon annularis, Bl. t. 215, f. 2 ; Gmel. Linn. p. 1262 ; Bl. Schn. p. 219 ; Shaw, Zool. iv, p. 330, 

 pi. 47. 



Holacanthus annularis, Lacep. iv. pp. 526, 533; Cuv. Reg. Anim. ii, p. 192; Cuv. and Val. vii, p. 178 ; 

 Cantor, Catal. p. 164 ; Bleeker, Verb. Bat. Gen. xxiii, Chastod. p. 26 ; Gunther, Catal. ii, p. 42. 



