84 POMACENTEIDiE. 



rapidly from the dorsal fin towards the snout. Teeth rather narrow, about thirty-six in 

 the upper jaw. Prgeorbital ring very narrow below the middle of the eye, its width 

 being about one-third of the diameter of the orbit ; breadth of the interorbital space 

 rather more than the diameter of the eye. The fifth, sixth, and seventh dorsal spines 

 longest, and longer than the last ; soft dorsal higher than long ; free portion of the tail 

 very short and elevated. 



Colour in a dried state uniform brownish olive, with darker lines along the series of 

 scales. Vertical fins blackish ; ventrals black ; a black spot superiorly at the angle of 

 the pectorals. 



Length 5 inches. 



Aden. 



HELIASTES, Cuv. 



291. Heliastes lepidurus. [712.] 



Heliases lepidurus, Cuv. fy Vol. v. p. 498. 

 Heliastes lepidurus, Giinth. Fish. iv. p. 63. 



Zanzibar. East-Indian archipelago. New Guinea. 



292. Heliastes opercularis, sp. n. Plate XI. fig. 2. [527.] 



D. g. A. T 2 D . L. lat. 29. L. transv. 3/9. 



Evidently closely allied to H. axillaris, Benn., and to H. xanthurus, Bleek. The 

 height of the body is contained three times and a half in the total length, or twice and 

 a half in that without caudal ; the length of the head is one-fourth of the latter. Teeth 

 in a narrow band, with an outer series of larger ones. Width of the prseorbital less 

 than half the diameter of the eye ; breadth of the interorbital space greater than the 

 diameter of the orbit ; prseoperculum distinctly emarginate on its posterior limb. Spines 

 of dorsal slender, the fourth and fifth the longest, thence they decrease gradually in 

 length, the last being equal to the second ; soft portion much higher than long, one of 

 the longest rays is once and two-thirds the length of the fourth dorsal spine. Caudal 

 deeply forked. Second anal spine half the length of the head. Scales on the cheeks in 

 four series; prseorbital scaly. 



Colour brownish, the cutaneous sheath of each scale with a darker margin. A large 

 irregular black patch behind the gill-opening, a similarly coloured line along the posterior 

 margin of the prwoperculum, a large black spot around base of pectorals, a smaller 

 oblong one on superior surface of ventrals, and a still smaller irregular spot on the 

 central caudal rays. Dorsal and anal black, with light posterior margins; caudal 

 brownish, with upper and lower edges black and posterior margins light. 



Length 5f inches. 



Zanzibar. 



