348 PRISTIPOMATII)^. 



rounded, without any denticulations whatever; the scales of the cheeks 

 do not extend on its limbs. The operculum is irregularly quadran- 

 gular ; its posterior side is emarginate, the inferior straight, obliquely 

 ascending backwards. The sub- and interoperculum are covered with 

 deciduous scales, like the operculum ; their inferior margin is slightly 

 convex. 



The dorsal fin is not very deeply notched \ the length of the base 

 of the spinous portion is shorter than of the soft, and its distance 

 from the caudal is one-third only of that from the end of the snout ; 

 its origin is above the base of the ventral, its end a little before the 

 vertical from the end of the anal fin. The spines are rather slender, 

 but not flexible : the first is minute ; the second the highest, and 

 2i in the height of the body ; the third is a little, the fifth and sixth 

 considerably shorter ; the last three are nearly equal in length, and 

 2j; in the length of the second. The fii'st ray equals the sixth spine ; 

 the other rays not differing very much in height, and forming a 

 slightly convex margin, with the membrane between deeply notched. 

 The caudal fin is deeply forked, the middle and shortest ray being 

 one-fifth only of the length of one of the outer and longest rays ; 

 the lobes are equal, and one-fourth of the total length : small, thin, 

 and deciduous scales extend over the basal third of each lobe. The 

 origin of the anal fin faUs beneath the third ray of the dorsal, its 

 end a little behind that of the dorsal. The length of its base is 

 more than its distance from the caudal, and exactly equals the distance 

 between the anterior margin of the eye and the hinder end of the 

 operculum ; it moves like the dorsal in a scaly sheath. The anterior 

 spine is minute ; the second rather stronger than the strongest of the 

 dorsal ; the third is more slender, but longer than the second, it is 

 more than half of the second dorsal spine, and about one-sixth of the 

 height of the body. The fii'st ray is rather longer than the last spine, 

 and the following rays diminish in length, so as to form a concave 

 margin of the fin. 



The pectoral fin is elongate, the middle rays being the longest ; it 

 reaches beyond the origin of the anal fin, and is one-fourth of the 

 total length. The base of the ventral fin falls behind that of the 

 pectoral ; it does not extend to the vent, and is one-seventh only of 

 the total length ; it is composed of one slightly curved spine, three- 

 fourths of the adjacent ray, and of five rays, the last of which, as 

 in all the species of Gerres, is split into two branches to its base, so 

 that there is an appearance of the fin having six soft rays. 



The scales are deciduous, not ciliated, higher than long: one of 

 the largest covers one-third of the eye. There is an exceedingly 

 long squamous flap at the exterior base of the ventral. The lateral 

 line is very sHghtly curved. 



The teeth are minute, in villiform bands. 



The back is reddish olive, vdth some reflecting longitudinal streaks ; 

 the sides and the belly are silvery. The vertical fins are blackish ; 

 the dorsal fin with a black edge. In the younger of the specimens 

 the blackish colour of the dorsal fin forms two longitudinal series of 

 spots. 



