6, 



FAMILY, I— PERCIDiE. 53 



having its double edge sen-ated, two or three coarser teeth being at the angle : lower margin of interopercle 

 entire. Two or three small and very blunt denticulations at the posterior superior angle of the orbit and in a 

 line between it and the posterior-superior angle of the opercle. Teeth — villiform in the jaws, in a single 

 ^-shaped row in the vomer, and also present on the palatines : tongue usually with a narrow band along its 

 centre. Fins — dorsal spines strong, transversely lineated, giving a sen-ated appearance to the second, which is the 

 longest, and equal to the length of the head behind the front margin of the orbit, or even slightly longer : the 

 ventral does not extend to the anal : second anal spine the strongest and nearly as long as the tliird, "which 

 almost equals the third of the dorsal : caudal deeply forked, upper lobe usually the longer. Lateral-line — con- 

 tinuous. Pseiulohrancldce — well developed. Colours — silvery, with purplish reflections : a bright silvery line from 

 the eye to the caudal fin : interspinous membrane between the second and third dorsal spines dark. 



In examining six specimens of this fish, the following were the proportions of the highest dorsal spine 

 as compared with the length of the body. 



No 1, total length 3^% inches: without candal fin 23% inches: dorsal spine /„ inches or 3f of length of body. 



J5 " —10 • " 5) )) 1 " »' 7 55 " 



'>_«_ . _s_ Qi 



" '» *~10 • )1 5» )) 1 U 1' !' '-'S 5» »1 



3-'- • -S- S^ 



!» " "10 ■ 5? n 51 1 O 55 55 '-> 8 55 55 



3_=- • _?_ -^8 



55 55 *-* 1 • 55 55 55 10 55 55 'J<f. 55 55 



55 55 •-'10 '55 55 55 1 55 55 ^9 5, 



The specimens in the British Museum, marked A. Batjanensis, Bleeker, have the preorbital serrated and 

 not entire as stated in the Catalogue (Vol. i, p. 22-5), and otherwise closely resemble this species. 



Hrthitat. — This common species extends from the Red Sea through those of India to North Australia : 

 it ascends rivers and estuaries, attaining to six inches in length. 



6. Ambassis nalua, Plate XV, fig. 4. 



Chanda nalua, Ham. Buch. Fish. Ganges, pp. 107, 371, pi. 6, f. 36 ; Cantor, Catal. p. 6. ? 

 Ambassis nalua, Cuv. and Val. ii, p. 182 ; Bleeker, Perc. p. 29, and Ambassis, p. 94 ; Giintlier, Catal. i, 

 p. 22.5. 



Ambassis Commersonii, Kner, Novara Fische, p. 41. 

 Kyoung-ma-sah, B\irm. 



B. vi, D. 71^1^1, P- 1-^5 V. 1/.5, A. ^:Vo5 C. 15, L. 1. 26-28, L. tr. 3/12. 



Length of head 1/4, of caudal 1/4, height of body 2/5 of the total length. Ez/es — diameter 2/5 of length 

 of head, nearly 1/2 a diameter from end of snout, and 1 apart. A great rise in the dorsal profile from the snout 

 to the commencement of the dorsal fin, but with a concavity over the eyes : lower jaw the longer : cleft of 

 mouth very oblique. The maxilla reaches to below the middle of the orbit. Preorbital rather strongly seri'ated 

 on both its inferior and superior borders : two short spines directed backwards at the posterior superior angle 

 of the orbit. Vertical limb of preopercle entire, except a few serrations just above the angle, its double edge 

 on its horizontal border strongly serrated, also the posterior half of the lower border of the interopercle. Teeth — 

 villifonn in jaws, vomer, and palate, a narrow band of teeth along the middle of the tongue. Fins — dorsal 

 spines strong, the second the longest and equal to the length of the head behind the front edge of the orbit : 

 the ventral does not quite reach to the anal : the pectoral extends to above the anal spines, the second and third 

 of the latter of the same length, and almost equal to the third of the dorsal fin : caudal deeply forked. Lateral- 

 line — continuous. PseuiJobranchire — present. Colours — silvery, with a burnislied lateral band : interspinous 

 membrane dark between the second and third dorsal spines : a dark longitudinal band along either caudal lobe. 



Cantor remarks, as observed by M. M. Cuvier and Valenciennes, that this species differs from Lufjanus 

 rjymnocephalus, Lacep. (syn. Sciama safgha, Forsk. ? Centropomus amhassis, Lacep. Ambassis Comiuersonii, Cuv. 

 and Val.) by its comparatively shorter head, blimter muzzle and greater depth of the body (p. 6). Also in 

 this species the interopercle is serrated, whilst it is entire in the Ambassis Commersonii* 



Sabitat. — Calcutta in fresh and brackish water : Malabar coast and Andamans to the Malay Archi- 

 pelago. 



7. Ambassis interrupta, Plate XV, fig. 5. 



Bleeker, Ceram, ii, p. QQQ, Atl. Ich. Perc. t. Ixx, f. 5, and Ambassis, p. 97 : Giinther, Catal. i, p. 226. 

 Ambassis viacracanthus, Day, Proc. Zool. Soc. 1870, p. 681. 



B. vi, D. 7/^.Vo5 P. 13, V. 1/5, A. -g-.i^-, C. 18, L. 1. 28, L. tr. 6/8. 



Length of head 2/7, of caudal 2/7, height of body 2/5 of the total length. Eyes — diameter 2/5 of length 

 of head, 1/2 a diameter from end of snout, and 3/4 of a diameter apart. Lower jaw the longer : cleft of mouth 

 oblique. The maxilla reaches to below the front edge of the orbit. Preorbital with both its upper and 

 lower edges serrated. Anterior edge of orbit sei'rated and two spines at its posterior-superior angle. Vertical 

 limb of preopercle entire, the double edge of its horizontal limb serrated : interopercle with four denticulations 

 at its angle. Teeth — villiform in jaws, vomer and palate. Fins — second dorsal spine nearly half the length of 

 the body in the adult ; the ventral does not extend to the anal fin : third anal spine slightly the longest : 



* In some rare cases the posterior inferior angle of the interopercle has 2 or 3 very badly marked sen-ations in A. Commersonii. 



