242 ACANTHOPTERYGII. 



1/3 to 2/5 of the height of the body, its third spine anteriorly serrated. Caudal forked. Scales — small but 

 distinct, present on breast and chest. Lateral-line — becomes lost at nearly the end of the free portion of the 

 tail : it consists of above 60 tubes placed on a row of plate-like, rounded scales. Colours — silvery, -with vertical 

 zigzag lines passing down the back : base of pectoral posteriorly black : upper edge of dorsal darkish. 



Habitat. — Seas of India to the Malay Archipelago. The specimen figured (life-size) is from Madras. 



9. Equula insidiatrix, Plate LI, C. fig. 5. 



Zeus insidiator, Bloch, t. cxcii, f. 2, 3 ; Gmel. Linn. p. 1221 ; Bl. Schn. p. 95 ; Shaw, Zool. iv, p. 284, 

 pi. 41 ; Lacep. iv, pp. 572, 574. 



Equula insidiatrix, Cuv. and Val. x, p. 98 ; Cantor, Catal. p. 151 ; Bleeker, Makr. p. 84 ; Jerdon, M. J. 

 L. and Sc. 1851, p. 138 ; Peters, Mon. Akad. Berlin, 1868, p. 262 ; Giinther, Catal. ii, p. 504 ; Day, Pish. 

 Malabar, p. 102. 



Paarl coorchee, Mai. 



B- v, D. ^zhr, P- 18, V. 1/5, A. &, C. 17. 



Length of head from 4f to 5, of caudal 5, height of body from 2£ to 2f in the total length. The 

 young are much more elongated. Eyes — diameter 2\ in length of head, 3/4 of a diameter from end of snout, 

 and 3/4 to 1 apart. Abdominal profile more convex than the dorsal one. Premaxillaries very protractile, the 

 length of their hind limb equalling 1/8 of that of the total length : and when fully protracted the mouth remains 

 directed somewhat upwards, when closed the mandible is almost vertical and not concave. Interorbital cavity 

 triangular. The middle third of the supraorbital edge finely serrated. One or two minute supraorbital spines 

 at the anterior-superior edge of the orbit directed backwards, the external when two are present the stronger. 

 The maxilla reaches to below the front third of the eye. Lower edge of preopercle minutely serrated, occasionally 

 almost smooth. Teeth — minute, in 1 or 2 rows. Fins — dorsal spines weak, smooth : the first minute, the second, 

 third, and fourth subequal in length and equal 1/3 the height of the body. Pectoral nearly as long as the head. 

 Second anal spine equals the diameter of the orbit. Ventral minute, reaching 1/2 way to anal. Caudal forked. 

 Scales* — minute over the body, breast, and chest, but not at the base of the pectoral fin. Lateral-line — passes 

 nearly level with the back and is generally lost near the tail, but sometimes as far forwards as below the middle 

 or last third of the dorsal fin. Colours — back bluish-silver, abdomen whitish-silver, the whole being glossed over 

 with a slightly golden tint. The upper surface of the head, cheeks, and lower jaw, all of burnished silver, often 

 a black streak from the eye to the throat, joining that of the opposite side : a dark mark in the axilla. Three 

 or four horizontal lines of black spots, with bronze reflections, form from eight to ten vertical bands descending 

 along the upper half of the body. Spinous dorsal tipped with black : ventral white : pectoral light yellow : 

 caudal yellowish, and stained at the end with brown. 



Habitat. — Seas of India and the Malay Archipelago : it is said to be occasionally captured in fresh 

 water. 



10. Equula ruconius, Plate LI, C, fig. 4. 



Chanda ruconius, Ham. Buch. Fish. Ganges, pp. 106, 371, pi. xii, f. 35. 



Equula interrupta, Cuv. and Val. x, p. 102 ; Bleeker, Ich. Fauna Beng. 1853, p. 96, and Makr. p. 85 ; 

 Ganther, Catal. ii, p. 504 ; Peters, Monats. Ak. Berlin, 1868, p. 262 ; Kner, Novara Fische, p. 169. 

 Equula ruconius, Cuv. and Val. x, p. 79 (not Day, P. Z. S. 1869, p. 302). 



B. v, D. J-g, P. 18, V. 1/5, A. T \, C. 17. 



Length of head 4|, of caudal 4|, height of body (1J to If in the young) one half of the total length. 

 Eyes — diameter 1/3 of length of head, 1 diameter from end of snout, and also apart. Abdominal profile much 

 more convex than that of the abdomen, a concavity over the occiput. Premaxillaries very protractile, the 

 length of their hind limbs equalling 1/12 of the total length, the mouth as in E. insidiatrix. Last half 

 of supraorbital edge minutely serrated ; one or two spines close to hind nostril. The maxilla reaches to below 

 the front edge of the orbit. Lower edge of preopercle serrated, most coarsely so anteriorly. Teeth — in a single, 

 minute, and deciduous row. Fins — second dorsal spine the longest, equal to 2/7 of the height of the body, the 

 third serrated anteriorly in its lower third. Pectoral 3/4 the length of the head. Ventral reaches half way to 

 anal, second anal spine equals the diameter of the orbit. Caudal forked. Scales — very deciduous, apparently 

 often absent and usually so above the lateral-line, they are from two to three times the size of those 

 in E. insidiatrix, and are often extended on to the chest. Lateral-line — in single tubes, usually ceasing below 

 the middle of soft dorsal, but sometimes continued to its last third. Colours — back bluish-silvery, abdomen 

 silvery -white. A well marked black streak from the anterior edge of the eye to the throat, joining that of the 

 opposite side. A dark spot on the upper part of the opercle, back of the base of the pectoral black. Vertical 

 lines of black marks having bronze reflections descend down the upper third of the body, and are often sub- 

 divided into spots. Spinous dorsal tipped with black. 



This is much more frequently captured in estuaries and tidal rivers than E. insidiatrix, it is common in 

 the Hooghly at Calcutta. Chanda (ambassis) ruconius, McClelland, C. J. N. H. ii, p. 586, has erroneously 

 been referred to this species. His specimens came from the Punjab, where no Equula exists. It is doubtless an 

 Ambassis, and probably the A. ranga, H. B. 



* In a specimen from Akyab, only If inches long and 7/10 high, the lower edge of the preopercle is rather coarsely serrated, 

 and there are no scales on the body. 



