244 



J,ONG-SPINED CH^TODON. 



is a conical projection, not easily distinguished, on account of the deep black hue with 

 which it is colored, and a similar protuberance arises on that part of the fish which 

 is by courtesy termed the nape of the neck. It may be seen in the figure, about half- 

 way between the snout and the beginning of the dorsal fin. Three very broad black 

 bands are drawn across the body ; their edges are sharply defined, as if a painter had 

 drawn them with black varnish. The foremost band commences at the first dorsal spine, 

 and sweeps over the neck, upper part of the head, snout, and chin, the eye being im- 



LONG-SPINED CILTODON. Heaiochus monoceros. 



bedded, as it were, in the black ground, and shining with great vividness on account 

 of the contrast. The second band passes from the fifth to the seventh dorsal spines 

 to the abdomen, being rather narrow at the top, and widening as it passes down- 

 wards below, but not comprising the pectoral fin. The third band starts a little below 

 the central streak, and is drawn rather obliquely over the body, through the hinder 

 portion of the anal fin. A remarkably fine specimen in the British Museum was 

 captured off the Mauritius. 



THE members of the curious genus to which the SEMILUNAR HOLOCANTHUS belongs 

 are remarkable for a very strong, sharp-pointed, thorny spine with which the praeoper- 

 culum is armed. These curious fish are found in almost all tropical seas. 



