112 ACANTHOPTERTGII. 



A. Scales small. 

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



ChcptDihn imperator, Bloch, p. llC-t, t. 19-1 ; Gmel. Linn. p. 1255 ; Bl. Schn. p. 217. 



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

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

 t. xli', fig. A ; Klunz. Verb. z. b. Ges. Wien, 1870, p. 787. 



B. vi, D. W-W. P- 21, V. 1/5, A. ^»^, C. 17. 



Leno-tli of head 1/4 to 3/13, of caudal 1/7, heiglit of body 1/2 to 4/7 of the total length, ii/j/es— diameter 

 1/3 to 1/4 of the length of head, \\ to \\ 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 limb 

 of preopercle rather oblic[ae and sen-ated, 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, gi-aduaUy 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 thii'd the longest and equal to the last of the dorsal or the head excluding the 

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

 tince alone the back : about nineteen canary-coloured lines pass upwards to the dorsal, horizontally to the 

 caulial, 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 Kidloo JcoU meen and Holacantlms imperator, exists 

 amongst Sir Walter ElHot's figures of fish. 



Habitat. — Prom the East coast of Afi-ica through the seas of India to the Malay Archipelago. 



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



Cliaiodon Nicoharceiitfis, 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, RuppeU, N. W. Pische,p. 32, t. x, f. 2 ; Bleeker, Amb. iv, p. 414; Giinther, Catal. ii, 



p. 53. 



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

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



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

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



B. vi, D. iti*, P. 19, V. 1/5, A. ^'^, C. 18, L. r. WM- 



Length of head 1/4, of pectoral 1/4, height of body 1/2 to 4/9 of the total lengtb. 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, denies— 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 sUghtly ciu-ved 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 thl^re are reticulated blue lines between the broad white band behind the eye and on one 

 desce'ndino- from the centre of the spinous dorsal. In the adult (H. semicirculatus) the vertical bands have a 

 more curv'ed direction, the convexity being forwards. In the Nicohariensis 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 'I^ inches in length, the preopercular spines are bifurcated at their extremities, in a 

 specimen in the British Museum {\^ inches) tbey are not so. 



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

 H. lineatus, Riipp. H. crendescens, Riipp. Cha-todon asfur, var. b. Forsk. Holacanthus haddaja, C.V., Chcetodon 

 maculosus, 'Forsk.=B:olacanthus maculosus, Holacanthus aruset, Lacep., Pomacantlms asfur, Lacep. as varieties 

 of Chcetodon asfur, Forsk.— Holacanthus asfur. 



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



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



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



pi. 47. 



' Holacanthis annularis, Lacep. iv. pp. 526, 533; Cuv. Reg. Anim. ii, p. 192; Cuv. and Val. \\\, p. 178; 

 Cantor, Catal. p. 164 ; Bleeker, Verb. Bat. Gen. xxiii, Chaitod. p. 26 ; Giinther, Catal. u, p. 42. 



