BALISTES. 



293 



As this genus is now circumscribed, it still includes 

 a considerable number inhabiting all seas. Lamarck 

 characterises twenty-nine of the two first sections, of 

 which three or four are fossil species, and four of the 

 second. De France enumerates sixteen fossil species, 

 some of which are found in this country ; they are, 

 however, by no means common. 



A further arrangement of this genus might be made 

 with propriety by separating the species having six 

 valves in the operculum, and a due consideration 

 of the internal portion which some of the species 

 possess double. 



BALISTES (File Fish). A genus of fishes belong- 

 ing t.o Cuvier's order, Plectognatheg (soldered or 

 united jaws), and to the second family of that order, 

 Sclcrodermis (hard skin). The name batistes has 

 been given in consequence of the length of the dorsal 

 spine, by which the fish appear to move like the 

 arm of a cross-bow. The characters of the order 

 will be explained under PLECTOGNATHES, and that 

 of the family under SCLERODERMES. But it may not 

 be improper to mention here that all the order are 

 intermediate in their general characters between the 

 bony and the cartilaginous fishes, their skeletons beiny 

 formed of matter which is partially flexible, and the 

 different portions partially soldered together. This 

 is not so much the case as in the cartilaginous fishes ; 

 and it is more conspicuous in the bones of the head, 

 more especially those connected with the upper jaw, 

 than in any other part of the body. 



It is a general law that those fishes which have a 

 deficiency of bony matter in the skeleton have it 

 precipitated, or accumulated, in some form on the 

 surface of their bodies, as in the thorns on skates, the 

 tubercles on sharks, or the plates upon sturgeons. 

 . They are thus as it were intermediate between 

 vertebrated and invertebrated animals, having the 

 skeleton of the former, and partially also the shell, 

 crust, or other form of covering, of the latter ; and the 

 condition of these two parts appears to be pretty 

 constant as a whole, but to fluctuate in the two, some- 

 times going more to the one, sometimes . more to the 

 other. 



In the two families of Plectognathi, the disposition 

 of the osseous matter, though it is to the surface in 

 both, is very distinct in each, so as to form a leading 

 .character. In the one division it goes to the jaws, 

 and covers them with plates of ivory, which may be 

 considered as continuous teeth, or teeth soldered by 

 nature into one piece, though they have been styled 

 gynmodontet or " naked teeth." In the division 

 which includes the genns balistes, it goes to the ex- 

 ternal covering of the body, in osseous granulation 

 over the skin, in strong spines to the fins, or in both. 

 The latter is the case with balistes, which gets their 

 common English name of " file fish," from the skin 

 being granulated like a file, and the name batistes from 

 the dorsal spines, or long rays in their first dorsal 

 fins, which are not only much produced, but articu- 

 lated to a peculiar bone, which enables them to per- 

 form much more motion than the dorsal appendages 

 of many other fishes ; but what function that motion 

 performs in their economy is not known. 



The general characters of the genus are, the muzzle 

 long and conical and the mouth small (though these are 

 rather characters of the order), the body compressed ; 

 each jaw furnished with eight teeth in a single row, 

 the points of which are often trenchant, or partially 

 chisel-shaped, and thus fitted for biting sea weed. 



Their skin is scaly or granulated, and the scales 

 are of more consistent matter than those of the bony 

 fishes, but they cannot be considered as absolutely 

 bony, like the tubercles and plates on the cartilaginous 

 fishes. The first dorsal fin is composed of one or 

 more spines, articulated to a peculiar bone, and that 

 bone is connected with the bones of the cranium. 



The first dorsal fin is more or less moveable in the 

 direction of the mesial plane of the body. The second 

 dorsal fin is soft and generally large ; but it varies in 

 the different species : it is, however, in general, placed 

 immediately above the anal fin, and the two very 

 often resemble each other. The caudal fin varies very 

 much in its form, being in some crescent-shaped, with 

 long projecting points at the terminations ; in others 

 it is nearly square ; in others again it is rounded, and 

 on some it is nearly lance shaped. Many of the 

 species are without ventral fins ; but all have bones 

 in the sides of the cavity of the body, which are 

 articulated to the shoulder-bones. These bones are, 

 in some of the species, capable of a very considerable 

 degree of motion ; and sometimes they are armed 

 with spines at their extremities, and may perhaps be 

 considered as the rudiments of ventral fins, and be in 

 some way auxiliary in the process of swimming. 



The gill-opening of these fishes is a mere slit, 

 without gill-lid, or gill-flap ; so that in this respect, 

 as well as in some others, they approach the character 

 of the cartilaginous fishes. 



The species are very numerous, and generally 

 inhabitants of the torrid zone, and invariably of the 

 ! warmer parts of the ocean, none of them being found 

 near the poles, or in very high latitudes ; but there 

 is at least one species in the Mediterranean, the one 

 from which the genus was at first named by Artedi. 

 They are usually found in the shallow water near the 

 rocks, where their colours, which in many of the 

 species are bright and finely contrasted with each 

 other, have a very brilliant effect. They are said to 

 feed upon sea-weed, and also upon the polypi by 

 which the coral rocks of different sorts are formed ; 

 and when they feed upon the latter, their flesh is said 

 to be poisonous, or at any rate unwholesome. It is 

 probable, however, that tiieir principal food is sea- 

 weed, at least in those which have trenchant teeth ; 

 and Cuvier mentions that as being the substance he 

 found in the stomachs of those which he dissected. 

 The flesh of none of the species is valuable as an 

 article of food. It is dry and tasteless, and in many 

 of the species it is to be suspected, if not actually 

 unwholesome. 



The sizes, shapes, colours, and other external 

 characters, which, from the very imperfect knowledge 

 we have of their habits, are almost the only ones of 

 fishes, vary so much that they have been divided 

 into four subgenera, batistes, properly so called, 

 monacanthus, alutercs, and triacanthus ; but, so far as 

 is known, their habits all resemble each other. 



The bat'istes, properly so called, are those which, 

 from the texture of their skins, more immediately 

 merit the name of " file fish." They are covered 

 with moderately large tubercular scales of a rhom- 

 boidal form and very hard texture, which are not 

 imbricated or overlapping each other, like the scales 

 of ordinary fishes, nor are they, as is generally the 

 case with these, free at their posterior edges ; but 

 adhere closely to separate portions of the skin, with 

 channels between. 



There is here one point worthy of remark : the 



