176 DR. RICHARDSON'S DESCRIPTION OF AUSTRALIAN FISH. 



voyage'. The membrane near the base of the anterior edge of the spine feels granular 

 to the touch, probably the effect of corrugation by the alcohol, but the bone is smooth. 

 The fin is closely attached to the groove of the spine, the rays being about one-fourth 

 part shorter, but a slip of membrane runs up to near the tip. The base of the fin is 

 fleshy, and the rays are too fine and close to be enumerated. A thin membrane attaches 

 the posterior part of the fin to the back, but the point of the spine when laid down 

 reaches behind it. The second dorsal commences behind the base of the ventrals, or 

 nearly opposite to the posterior verge of the anus. It has a triangular elevation which 

 occupies more than the anterior third of the fin, and the fin is suddenly curved into the 

 form of narrow and slightly decreasing edging of the back, which terminates about an 

 inch before the first under caudal. Behind it the summit of the back is flat, but not 

 broad up to the commencement of the upper caudal. The first under caudal is trian- 

 gular and slightly falcate, its height exceeding twice the length of its own base and being 

 greater than that of the second dorsal. Immediately behind it, but distinctly separated 

 from it by a little pit, rises the second caudal by a lobe nearly as high, but which gra- 

 dually lowers in a falcate manner until it ends in the acute tip of the tail. The upper 

 caudal being exactly opposite to the whole length of the second under one, is at its 

 commencement merely a thick ridge of skin, which gradually narrows as it approaches 

 the tip of the tail, the rays at the same time becoming more apparent. The pectorals 

 have a scalene triangular form, with the inferior angle rounded off, and are more pointed, 

 but neither so large nor so broad as those represented in Shaw's figure of antarcticus (Gen. 

 Zool.) . Tlie oval cartilaginous plates which occupy the cavities lying before the ventrals 

 are covered on their posterior halves by small spiny teeth, each tooth being composed 

 of two rows of from three to six pectinated points directed towards the head. The 

 claspers are as long as the ventrals. The female wants these claspers and plates, and the 

 knob on the forehead. The ventrals in her are cut nearly even behind, but are broader 

 on the exterior than on the mesial edge. 



The colours of the male were not noted, but the female, when newly taken from the 

 brine in which it had been well-preserved, had a general light grayish-nacry or silvery 

 tint blending into blackish-gray along the back. The lateral Une traversed an ill-defined 

 dark stripe, and on the side above the pectoral there was a large oblong, milk-white 

 patch, which had also a dark border that gradually softened off into the general hue. 

 The fins and the top of the head were also dark. 



The subjoined table of dimensions will furnish the means of ascertaining the propor- 

 tions of the members for comparison with other species, but the male not having been 

 measured till after it was mounted, I have been compelled to omit some of the re- 

 sults, as being uncertain. 



Anatomical observations. — The cranium forms a large and deep mesial bony crest 



' A small part of the spine of the male specimen is broken, but that of the female is entire, and neither 

 appears ever to have been serrated. 



