DR. RICHARDSON'S DESCRIPTION OF AUSTRALIAN FISH. 167 



& vertical diameter equal to half its longitudinal one. The height of the tail is about 

 one-fifth of that of the body, and its length comprised between the three vertical fins 

 equals one-tenth of the entire length of the fish, caudal fin included. The profile of the 

 head is nearly straight from the dorsal spine to the lips : the under profile is more 

 convex, though somewhat undulated, and when the pelvic bones are fully depressed the 

 belly is protuberant, while the back between the first and second dorsals is nearly 

 straight. The thickness of the body is equal to one-third of the height. 



The whole skin is densely studded with minute conical spines directed backwards. 

 On the sides these spines appear when examined by the microscope to be arranged in 

 innumerable vertical or inclined rows, five or six in a row, with a few solitary ones be- 

 tween. This arrangement is more distinctly seen on the belly, where the skin is lax, 

 and the spaces between the rows or scales as they may be termed, wider. In many 

 places the rows are double, and the little spines more acute. Round the eye, about the 

 gill-openings, and on the head generally, the spines are shorter, more obtuse, and either 

 solitary, or so clustered that their separation into rows can no longer be made out. In 

 the axilla of the pectoral fin, the spines are obtuse and very minute, but their distribu- 

 tion in separate rows or scales is very readily seen there. To the naked eye the skin 

 merely appears to have a close-shaven villous structure. 



Rays.—B. 6-6 ; D. 2|-35 ; A. 34 ; C. 12 ; P. 14. 



The dorsal spine stands over the posterior half of the orbit, and above the gill-open- 

 ing. It is rounded and tapering with a groove behind, which runs nearly to its tip, 

 and is armed on its margins with spinous teeth pointing downwards. The anterior sur- 

 face of the spine is closely studded with very obtuse, minute teeth, the two middle 

 rows being larger than the rest. There is a short spine, or bone involved in the mem- 

 brane behind the principal spine, and serving as a trigger to it, to fix it in an inclined 

 or erect position. This small spine requires to be depressed before the principal one 

 can fall back into the dorsal groove. The second dorsal commences a little anterior to 

 the vent and terminates opposite to the end of the anal. Both these fins are mode- 

 rately arched, being highest at the commencement of the second third of their lengths. 

 The caudal is regularly rounded when expanded, and when closed its rays are all equal 

 in length. The rays of all the fins are rough at the base, the asperities of the pectoral 

 however being so minute as to require a good lens to exhibit them. On the caudal the 

 minute spines are very crowded and regular, and extend to the tips of the rays, yet so 

 that the broad rough surfaces of the alternate rays only appear on each side of the fin ; 

 but the uppermost and undermost ray are simple and broadly rough on both sides ; 

 the others are divided. The rays of the second dorsal, anal and pectoral, are all simple 

 and jointed. The pelvic bone projects very little through the integuments, showing 

 merely a small knob, rough with minute obtuse spinous points. The integuments of 

 the belly are somewhat lax, giving a little play to the pelvic bone, but there is no ex- 

 tensible dewlap. 



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