230 LAMARCK'S H0L0CANTHUS. 



The Beaked Chsetodon inhabits the Indian and Polynesian seas, and has been taken off 

 the west coast of Australia, where it is usually found in or near the months of rivers. Over 

 the head and body of this species are drawn rive brownish cross-bands edged with darker 

 brown and white, and in the middle of the soft dorsal tin there is a rather large circular black 

 spot edged \\ illi \\ liiif. 



Several other species of this genus are recognized, one of which, the Long-beaked 

 Ch.etodon {Chelmo longirostris), is truly remarkable for the exceeding development of the 

 snout, which considerably exceeds half the length of the head. This species is also notable 

 for a large triangular patch of jetty-black, which covers the upper surface of the head, the 

 neck, and the side of the head as far as the lower edge of the eye. There is also a circular 

 spot of the same hue on the anal fin. This species is a native of Aniboyna. 



A very remarkable fish adds to the singular shape of all the group the peculiarly 

 elongated dorsal spine from which it has received its name of Long-spined Chsetodon, or 

 Charioteer. It also well exhibits the scale-covered fins, a structure which is indicative of 

 the large family to which it belongs. Both scientific names are of Greek origin, the former 

 signifying a charioteer, the long slender spine representing the whip ; and the latter signifies 

 "single-horned," in allusion to the same peculiarity. 



The fourth dorsal spine of this species is enormously elongated and whip-like ; its use not 

 being as yet ascertained or even conjectured with any show of reason. Over each eye 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. 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 imbedded, 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 

 downwards 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. 



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 prseoperculum is 

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



Nearly forty species of this genus are now known, all of which possess some remarkable 

 peculiarity in coloring. There is, for example, the Ringed Holocanthus {Holocanthus 

 annularis), where the shoulder is decorated with a blue ring, and the body is marked with 

 six or seven arched blue stripes, all radiating from the base of the pectoral fin. The Spotted 

 Holocanthus {Holocanthus maculosus) has a number of black, semilunar spots on the fore 

 part of the body; the Ciliated Holocanthus {Holocanthus ciliaris) is marked with an 

 azure ring on the nape of the neck, and a number of blue spots and streaks about the head ; 

 the Emperor Holocanthus {Holocanthus imperator) has a number of blue lines upon the 

 head, chest, and anal fin, a large black spot on the shoulder, and the body decorated with 

 many waved, orange-colored streaks; and lastly, the Arched Holocanthus {Holocanthus 

 arcuatus), though not so brightly clad, is quite as striking a species as any that has been 

 mentioned, simply on account of the single arched stripe that is drawn along the body, from 

 the eye to the end of the dorsal fin, taking a slight upward curve like a bent bow. 



It is said of one of the species, Lamarck's Holocanthus {Holocanthus lamarcMt), that 

 the attachment between the sexes is very strongly developed, and that, if one individual be 

 captured, its mate will haunt the fatal spot, and even fiing itself ashore or into the net, in the 

 eagerness of its search. 



