the Ichthyology of Australia. 



121 



cies which enter into the genus show various gradations* in 

 the strength of their cardiform dentition ; and the teeth in 

 some being finely villiform, with small and scarcely projecting 

 canines, are in fact less efficient organs of retention than the 

 teeth of Centropristes nigricans, which are stated by Cuvier to 

 be all ( en fort velours.' The Centropristes scorpenoides, on 

 the other hand, has very short, densely crowded teeth, with 

 the dental surfaces curved and fitting into each other, and 

 evidently adapted for rubbing down or bruising soft sub- 

 stances rather than for retaining a living prey. This species 

 also differs from the other Centropristes, and approaches the 

 Serrani in the snout and suborbitar being scaly. The un- 

 usual strength and length of the second anal spine, being 

 proportionally greater than even in the Holocentri, is a peculiar 

 character. Mr. Gilbert has brought home three specimens 

 in spirits, together with several dried skins, all retaining the 

 configurations of the dark colour strongly defined, particu- 

 larly on the spines and fins. One of the dried skins has been 

 presented by Mr. Gould to the Museum d'Histoire Natu- 

 relle at Paris. The description of Quoy and Gaimard's spe- 

 cimen, contained in the £ Histoire des Poissons,' agrees exactly 

 with the examples from Port Essington, except in the state- 

 ment of the suborbitar not being scaly and the operculum 

 having only one acute point ; but the figure in the zoological 

 volume of Freycinet's voyage is characteristic enough to show 

 that there can be no mistake as to species. The markings 

 are not however so boldly defined in that figure as they still 

 appear on Mr. Gilbert's specimens. 



Form. — Snout gibbous, the cranium being arched between the 

 orbits both longitudinally and transversely. The head is concave 

 behind the orbitf and rises again to the beginning of the dorsal fin, 

 from whence to the end of the fin the profile of the back is mode- 

 rately and regularly arched : the curve of the belly is flatter. 



The length of the trunk of the tail is equal to its own height, or to 

 about one-third of the height of the body, which at the insertion of 

 the ventrals, where it is greatest, is exactly equal to the length of 

 the head, measured to the tip of the gill-cover ; the total length of 

 the fish exceeds thrice the length of the head by half the length of 

 the caudal fin. The greatest thickness is just above the pectorals, 

 and is equal to half the height ; the body thins off more rapidly to- 

 wards the back, which is rather acute, than towards the belly, which 

 is nattish and has some breadth before the ventrals. Towards the 



* The genus Prionodes of Mr. Jenyns exhibits a peculiar modification of 

 the teeth of this tribe, the species on which it is founded being in fact a Ser- 

 ranus with toothless vomer and palate bones. 



f This peculiarity is owing to the soft parts, and not to the form of the 

 skull, which is convex. 



