496 Dr. Richardson's Contributions to 



the tail, is an ellipse, whose axis is twice the length of its vertical 

 diameter. The ellipse is not however quite regular, being more taper 

 in its posterior half. This is compensated by the greater, though 

 graduated length of the dorsal and anal rays bordering that part of 

 the fish, so that instead of the rhomboidal outline usual in the genus, 

 these fins produce an ellipse more regular than that of the body, and 

 having a vertical diameter equal to the entire length from the end of 

 the snout to the tip of the rhomboidal caudal. 



The tolerably large orifice of the mouth is in the anterior apex of 

 the ellipse, and runs backwards and downwards with a moderate 

 curve : when it is shut, the oblique end of the lower jaw projects a 

 little beyond the intermaxillaries. The whole edge of the lower jaw 

 and the upper jaw near the symphysis are armed by short awl- shaped 

 teeth set rather remotely in a single row. On the lateral parts of 

 the upper jaw the teeth are minute, short and crowded, but also in 

 a single row. The roof of the mouth is toothless. The perfectly 

 smooth chevron of the vomer projects considerably, while the arti- 

 cular heads of the maxillaries are but just visible within the mouth. 



On the lower dilated and truncated end of the left maxillary there 

 is a small cluster of scales. The right maxillary is scaleless. Each 

 limb of the lower jaw is traversed by two furrows divided from each 

 other by an acute ridge, and the uppermost furrow on the coloured 

 side is lined by a row of small ciliated scales, which do not exist on 

 the other side. 



The head is flattened on the pale side, and the nostrils of that side 

 are much nearer the dorsal or mesial line than the left ones are. The 

 eyes are on the left side close to each other, and not much out of 

 the same vertical line, the upper one being but a very little poste- 

 rior to the under one. The orbits are bordered posteriorly at a little 

 distance by a line of slightly raised tubes with porous mouths, the 

 line belonging to the under eye being a semicircular one, while the 

 upper one encloses an acutely triangular area whose apex terminates 

 in a slight but evident ridge, which runs to the occiput and is covered 

 with scales like the adjoining parts. The disc of the lower limb of 

 the preoperculum is roughened by irregular tubular elevations, co- 

 vered with epidermis and a very few interspersed scales ; the upper 

 limb is smooth, the rest of the opercular pieces and the whole cheek 

 is densely scaly. The interoperculum has an oval form, and is longer 

 and wider than the suboperculum. The edges of all the pieces of 

 the gill- cover are smooth. A flexible cartilaginous tip extends from 

 the suboperculum under the operculum to the membranous edge of 

 the gill-cover, as is usual in most acanthopterygian genera. 



Rays:— Br. 7; D. 73; A. 59; P.l|ll; C.15|;V. 6-6. 



The (left) pectoral is obliquely rounded ; its second articulated 

 ray is the longest, and but just exceeds the first and third ; the under 

 ones are regularly graduated to the lowest, which is half the length 

 of the uppermost ones. There is a short, slender spine incumbent 

 on the base of the upper ray. The membrane is very delicate and 

 perfectly scaleless. The dorsal commences over the posterior nasal 

 orifices, and the membranous edge of its first ray turns towards the 



