88 DR. RICHARDSON'S DESCRIPTION OF AUSTRALIAN FISH. 



running into indistinct vertical furrows on the limb of the preoperculum : they do not 

 show in the skeleton. The spines which arm the head are all stiletto-shaped, more or 

 less triangular, and very acute. The preorbitar tapers anteriorly into a stout acute 

 spine, which is marked by two ridges that diverge, and skirt the upper and lower 

 margins of the bone. The triangular space included between these ridges has less 

 lustre than the rest of the side of the head : on the margin of the pi'eorbitar, beneath 

 the hinder part of the inferior ridge, the little pits assume a radiated disposition. 

 The base of the preorbitar spine and adjoining edge of the bone is roughened by 

 minute granulations or serratures, distinctly visible only by the aid of a lens. There is 

 a similar very minute serrature on the orbital margins of the anterior and posterior 

 frontals ; but there are no teeth whatever on the circumference of the orbit, which is 

 rather larger than that of vanessa. In the skeleton the border of the anterior frontal 

 is marked by rays or furrows inclining backwards. There is a membranous furrow 

 within the under edge of the orbit, but it is not continued forwards to the nostrils so 

 evidently as in vanessa, being interrupted by the upper ridge of the infra-orbitar. The 

 preoperculum is an acute triangle, with a short base, to which the small interoperculum 

 is firmly united ; it has no horizontal limb, but a very acute spine (which is the smallest 

 on the head) projects directly backwards from its base or angle. The surface of the 

 interoperculum is ratlier coarsely pitted and somewhat radiated, and its posterior angle 

 is acute, but not spinous. The bony operculum has the general form of that of the 

 Gurnards, having a prolonged narrow point beneath, a smaller slender angular point 

 above overlying the rounded lobe of the membranous flap, and in the middle pos- 

 teriorly a spine which reaches backwards to the insertion of the pectorals. The 

 supra-scapular spines, which are rather longer than the opercular ones, reach to the 

 second dorsal ray, and the scapular ones, being the longest and most acutely triangular 

 of the whole, reach to about the sixth dorsal spine. 



Mouth. — The preorbitar spines form a notch at the end of the snout fully as deep as 

 in the Malarmats, and the membranous space behind has the usual horse-shoe shape. The 

 nostrils, as in other Gurnards, are close to it. The gape of the mouth is wider than in 

 vanessa, extending beyond the posterior nostril. The jaws are armed with very minute 

 villiform teeth, and there is a small transverse patch of still more minute ones on 

 the chevron of the vomer. The palate is smooth. The pharyngeal teeth are similar 

 to those of vanessa, but the outer row of rakers on the exterior branchial arch, instead 

 of being rounded with knobbed summits, are compressed, awl-shaped, very acute, and 

 fringed on the edge with hair-like teeth. On the other arches, and on the inner edge 

 of the outer arch, the rakers are merely sessile, wart-like knobs with bristly teeth, as 

 in vanessa. 



The scales are very minute, and appear like little pits on the surface of the integu- 

 ments, in which they are deeply imbedded. They can be seen distinctly only with the 



