the Tchthyology of Australia. 491 



evenly over tlie cheeks and gill-covers, so that the opercular bones 

 can scarcely be distinguislied from each other even in the dried spe- 

 cimen. The under border alone of the preoperculum is marked out 

 by a slight fold of the skin, and the membrane, which is stretched 

 from the fore-part of the interopei'culum to the under lip, is not at- 

 tached to the integument which covers the limb of the hyoid bone 

 over which it passes, a kind of pocket opening downwards being 

 thus formed. The posterior part of the interoperculum and rest of 

 the opercular pieces form one continuous surface with the gill-mem- 

 branes. The top of the head is flattish, and narrows gradually from 

 the nape to the snout. In the dried fish the flat space is bounded 

 laterally by a slightly elevated line which extends from the nostrils 

 to the nape. The upper edge of the orbit is prominent and rounded, 

 and a scarcely raised line is continued from it to the upper angle of 

 the gill-cover. The eye is large, and is only half the length of the 

 orbit from the orifice of the mouth, but twice as far from the gill- 

 opening. The mouth is small, but the true shape of its orifice can- 

 not be ascertained from the specimen, the under lip having been 

 injured. The maxillary widens gradually towards its lower end, which 

 is rounded away : it forms half the upper lip, which is arched, and 

 is received a short way under the bulging edge of the preorbitar. 

 The upper lip has no soft parts beyond the thin integument covering 

 the bone. There are no vestiges whatever of teeth either on the 

 jaws or roof of the mouth. A mucous canal with short branchlets 

 traverses the surface of the preorbitar, and closely skirts the orbit 

 beneath and behind. The gill-rays are strap-shaped, very thin and 

 flat. 



There are no scales on any part of the head. The scales of the 

 body are of moderate size, there being eighty-five rows and some 

 small ones between the gill-opening and caudal fin, on which the 

 scales terminate by an obtusely oval outline, and cover the central 

 rays more than half-way. The lateral line, with the exception of a 

 short inclination at its commencement, keeps a perfectly straight 

 course a little above mid-height from the gill-opening to the end of 

 the scales. The texture of the scales is thin and their form subor- 

 bicular. The basal half is divided by a notch into two rounded 

 lobes, and shows no other impressions than the very fine concentric 

 lines of structure. The uncovered portion is marked by about twenty- 

 six slightly divergent furrows, producing an equal number of rounded 

 ridges which terminate on the edge in acute points. 



Rays:— B. 4; D. 15; A. 11 ; C. 19§; P. 17; V. 11. 



The pectoral is small and situated low down ; it is composed of 

 seventeen rays and a short incumbent one, and there is a long pointed 

 scale beneath it. The acute point of the fin reaches nearly half-way 

 from the gill-opening to the ventrals. The dorsal fin commences 

 exactly midway between the mouth and base of the central caudal 

 rays : its margin is lunate with acute pohits, and the anterior point 

 is thrice as high as the posterior one. The first three rays are sim- 

 ple without visible joints, short and closely incumbent ; the rest are 

 2K2 



