the Ichthyoloyy of Australia. 



29 



Mungundju the posterior extent of the preorbitar is defined, and the 

 large suborbitar scales partly hidden by a band of small scales which 

 runs under the orbit and covers their bases. There are only six 

 rows of scales on the cheek of the Yapilli beneath the large subor- 

 bitar row, and all the convex surface of the preoperculum is naked : 

 in the Mungundju there are seven rows of scales on the cheek and 

 concave side of the preoperculum, and two rows of smaller ones on 

 the middle of the convex limb of the bone, similar to those which 

 exist in Dentex vulgaris; but in neither of the Mesoprions are the con - 

 vex and concave faces of the preoperculum divided from each other 

 by a distinct ridge, as in the Dentex. The whole surface of the inter- 

 operculum is clothed by four rows of small scales. In the Yapilli this 

 bone exhibits only a single row of scales, which are larger than those 

 on the cheek. The opercular scales are also larger than the cheek 

 ones in this species ; but in the Mungundju the difference between 

 their sizes is scarcely perceptible. In the Yapilli, the scales of the 

 suboperculum, which form a single row, gradually diminish in size 

 as they approach the tip of the gill-flap, and thus expose the lower 

 edge of the lobe of the bony operculum ; but in the Mungundju all the 

 scales of the row are of equal size, and they are tiled by the lower 

 row of opercular scales so as to conceal the junction of the bones 

 entirely. The two rows of large nuchal scales are rendered less 

 conspicuous in the Mungundju by the patches of small scales before 

 them being more extensive and encroaching over their bases. The 

 scaly surface in this species also extends to opposite the middle of the 

 orbit, while in the Yapilli it ends at the posterior angle of the eye, 

 and does not come so far as the vertex. The lower edge of the 

 preoperculum is much shorter than in Yapilli, and is quite entire ; 

 the angle is rounded and projects slightly, the ascending limb being 

 undulated slightly without any distinct re-entering curve. Two or 

 three irregularly scattered teeth are with difficulty discovered by the 

 aid of an eye-glass about the middle of the vertical limb, and on the 

 upper half of the rounded angle. The interoperculum is perfectly 

 destitute of the very slight thickening which the Yapilli shows in 

 the site of the tubercule of the Diacopes. The operculum is rounded, 

 as in the sparoid family, with a shallow re-entering arc which di- 

 vides the margin into two obtuse lobes, neither of them so wide as 

 the arc itself. The membranous edge of the gill-flap is very narrow, 

 and the tip of the suboperculum is not prolonged into an angular 

 flap beyond the operculum. The supra- scapular has one small notch 

 on its edge ; the edge of the humeral can scarcely be perceived 

 among the scales. 



Rays:— B. 7; D. 10|15 ; A. 3|10; C. lof ; P. 14; V. 1|5. 



The pectoral is pointed, but more suddenly acuminated, and con- 

 siderably shorter than in the Yapilli ; its point falls short of the anus. 

 The spines of the dorsal are more slender, and the soft part of the 

 fin is longer, not so high, and much less rounded than in the Yapilli. 

 The last ray, both of the dorsal and anal, is small, and may be only a 

 branch of the preceding one, so that fourteen and nine may be respec- 

 tively enumerated ; but as they are both distinct, and the fact cannot 



