the Ichthyology of Australia. 



19 



represented as ciliated. Two conspicuous, flat, triangular spines are" 

 shown on the operculum, and the edge of bone is rounded away in 

 a semi-circular arc, to a small angle adjoining the top of the gill- 

 opening. The pectoral is large, and has an oval outline, its central rays 

 reaching as far back as the anterior third of the anal. The ventrals 

 are also large, and reach to the anal. The second anal spine is the 

 largest of the three. The spinous dorsal moves in a densely scaly in- 

 tegument, there being only a triangular piece of smooth membrane 

 behind the top of each spine. The base of the soft dorsal is also scaly, 

 but the scales are not represented as advancing far on the anal. The 

 caudal is forked to the depth of one- third of its length. 



Rays :— D. 10|14 ; A. 3|7 ; P. 12 ; V. l|5 or 6 ; C. 15 :— Figure. 

 D. 10|20 ; A. 3|9 ; P. 16 ; V. l\6 ; C. 18 Schneider. 



The vertical height of the body is equal to one-half the length of 

 the fish, caudal excluded ; the length of the caudal being equal to 

 two-thirds of the height of the body. 



The total length of the figure, which is said to be of the natural 

 size of the fish, is eleven inches. 



Serranus Gilberti (Nob.), Gilbert's Serranus. 



No. 18. Mr. Gilbert's collection. 



This fish is stated by Mr. Gilbert to inhabit deep rocky 

 places near the entrance of the harbour of Port Essington. 

 It belongs to the group of spotted Serrani, of which the Merra 

 (Bl. 329.) is a typical species. The members of this group 

 are characterized in the c Histoire des Poissons' by the various 

 combinations they exhibit in the forms and denticulations of 

 the opercular pieces, the development of scales on the jaws, 

 the form of the dorsal fin, and the distribution of spots on 

 the body and fins. The phrases by which their peculiarities 

 are described, though sufficient to distinguish the species that 

 the authors of the work had actually under observation, are 

 inadequate, in the absence of correct figures, for the purposes 

 of the ichthyologist who desires to characterize fully the new 

 species or varieties which may fall under his notice. These 

 must, therefore, be proposed with some degree of hesitation, 

 until an opportunity offers for comparing the specimens with 

 ascertained examples of known species. The Port Essington 

 fish, which I have named after Mr. Gilbert, exhibits charac- 

 ters which I do not find combined in any Serranus described 

 in the c Histoire des Poissons.' 



Upper jaw and maxillaries destitute of scales ; the lower jaw and 

 snout clothed with minute ones. Ascending limb of the preopercu- 

 lum arched, finely toothed, and having a small slightly projecting 

 lobe at the angle, armed with five or six somewhat larger teeth : the 

 under edge of the bone is straight, and almost entire, there being 

 only some very indistinct crenatures perceptible by the aid of a lens. 



C 2 



