10S MEMOIRS OF THE QUEENSLAND MUSEUM. 



How acquired: — Collected by Dr. J. R. Tosh, and presented by him to 

 the Queensland Museum. 



Dimensions: — According to Bleeker this species attains a length of 500 

 millim. (On y voit quelquefois des individus d'un demi-metre de long.) 



HOLACANTHUS IMPERATOR (Bloch). 



-Japanische-Keizer Ruysch, Coll. Nov. Pise. Amboina, 1718, p. 37, pi. ix, fig. 1. 



Douwing-cammus Renard, Poiss. Moluques, i, 1718, pi. xvi, fig. 93. 



Empereur du Japon id., ibid., ii, 1719, pi. lvi, fig. 238 ; Valentyn, Amboina, iii, 1724, p. 4G2, 

 fig. 370. 



IJcton-djamban Valentyn, ibid., p. 362, fig. 51. 



Poisson-couronne id., ibid., p. 479, fig. 418. 



Chcetodon imperator Bloch, Ausl. Fisch., iii, 1785, p. 51, pi. exciv ; Bonnaterre, Encycl. Meth., 

 Ichth., 1788, p. 92, pi. xciii, fig. 384 ; Gmelin, Linnaeus Syst. Nat., ed. 13, i, 1789, p. 1255 ; 

 Schneider, Bloch Syst. Ichth., 1801, p. 217. 



Holaeanthus imperator Lacepede, Hist. Nat. Poiss., iv, 1802, pp. 527, 534, pi. xii, fig. 3 ; Cuvier 

 & Valenciennes, Hist. Nat, Poiss., vii, 1831, p. 180 ; Bleeker, Nat. Tijds. Nederl Ind., 

 iii, 3 852, p. 758; id., Act. Soc. Sci. Indo-Neerl., i, Manado and Macassar, p. 48 ; id., ibid., 

 viii, Celebes, etc., p. 35 ; Giinther, Brit. Mas. Catal. Fish., ii, 1860, p. 52 ; Bleeker, Nederl. 

 Tijds. Dierk., ii, 1865, p. 287 ; Klunzinger, Verh. zool.-bot, Ges. Wien, xx, 1870, p. 787 ; 

 Bleeker, Nederl. Tijds. Dierk., iv, 1873, p. 140 ; Giinther, Fisch. d. Sudsee, i, pt. 2, 1874, 

 p. 53, pi. xli, fig. A ; Bleeker, Pollen & Van Dam, Hist. Madagascar, pt, 4, 1875, p. 96 ; 

 Day, Fish. India, pt. i, 1875, p. 112, pi. xxviii, fig. 5 ; Seale, Occ. Pap. Bishop Mus., i, 

 No. 3, 1901, p. 104 ; Jordan & Seale, Bull. U. S. Bur. Fish., xxv, 1905, p. 349. 



Acanthochcetodon imperator Bleeker, Verh. Akad. Amsterdam, xvii, 1877, Chaet., p. 150 ; id., 

 Arch. Neerl. Sci. Nat., xii, 1877, p. 21 ; id., ibid., xiii, 1878, p. 41 ; id., Verh. Akad. Am- 

 sterdam, xviii, 1879, Maurice, p. 14. 



Type locality: — Moluccas. 



Depth of body 1-75 in its length ; dorsal and ventral contours about 

 equally elevated but not symmetrical, the former undulous and moderately 

 acclivous to the nape, which is convex ; beyond this it rises very gently to about 

 the 6th dorsal spine, whence it descends in a long curve to the caudal peduncle ; 

 ventral contour irregularly convex between the chin and the vent, thence curving 

 upwards more strongly to the peduncle, the least depth of which is 8-25 in the 

 length of the body. Width of head 1-5 in its length, which is 1-1 in its depth 

 and 3-5 in the body-length. Diameter of eye 2-15 in the length of the snout, 

 which is half that of the head: interorbital region convex, its width 1-5 time 

 the eye-diameter. Maxillary not extending to the vertical from the nostrils. 

 Preorbital entire, its width one third more than the eye-diameter. Hinder limb 

 of preopercle inclined well backwards, evenly serrated, the lower limb with or 

 without one or more strong teeth, the spine short and very strong (sometimes 

 double). 3-9 in the length of the head, and not reaching to below the middle of 

 the opercle. 



Scales small and ctenoid, the exposed area more or less completely spinu- 

 lose; the basal margin not or but little lobulate. Lateral line complete but 

 inconspicuous. 



