BALM. 



295 



resembling the canine teeth of mammalia. The dorsal 

 fin consists of two rays, or spines, quite detached from 

 each other ; the first large, the second very small. 

 The head is also much shorter, and the gape of the 

 mouth much wider than in most of the other species. 

 Instead of ventral fins, it has one large ray at the 

 caudal extremity of the abdomen, covered for the 

 greater part by the skin, or at all events united to it. 

 The skin is very rough, in lozenge-shaped tubercles ; 

 most of the rays of the fins are branched at their 

 terminations ; and there are, on each side of the base 

 of the tail, seven rows of spines curved forwards, 

 which lacerate the fingers, if the hand be drawn from 

 the head to the tail. 



BaKttet geograpJucus (monacantlnis, C.) is one of the 

 most remarkable species. Some notion of its form 

 may be obtained from the following figure. 



Balistes geographicus. 



The name geographicus is given from the markings, 

 which bear some resemblance to a map, the lighter 

 part the sea, and the darker the land, with its moun- 

 tains. The body is dark but compressed, the muzzle 

 produced, the mouth rather small, the eyes large ; 

 the spine of the first dorsal prominent ; and, in short, 

 it has all the characters which have been enumerated 

 in the short paragraph on mouoceros. It is found 

 both in the Atlantic and the Pacific, but only in the 

 warmer parts. 



Of Balistes pencil/igcrus (monoceres, (7.) the figure 

 has been already given. It is still deeper in propor- 

 tion toils length, and more compressed than geogra- 

 phicus. The rays of the second dorsal, the caudal, 

 and the anal fins* are, as in that species, bare or free 

 from the connecting membrane for some distance at 

 their points ; and they are also more conspicuous by 

 being farther apart from each other. The appendage 

 at the hinder part of the abdomen is not so decidedly 

 a ventral fin, though there is no doubt that it acts as 

 such when the fish swims. The most singular part of 

 its appearance, however, is the branched appendages 

 which are not only attached to the fins but scatterec 

 over the body and head. The first, or large dorsa 1 

 spine, is very much branched, and so is the second one 

 which is much smaller and placed considerably to the 

 rear of the first. The produced termination of the 

 cavity is fringed with these appendages, and there are 

 some of them on the forehead and cheeks. How they 

 may act in the water is not very well known, nor is it 

 easy to be imagined, as they appear to be singular 

 appendages to swim with. One would imagine that 

 like barnacles on a ship's bottom, they would imped< 

 its progress through the water ; and there is no doubt 



hat such would be the case if the body of (he fish 

 lad no flexibility, and if, like a ship, it were impelled 

 jy a force acting not in the water. But in the case of 

 fish, where both the moving power and tne fulcrum 

 rom which that power gets the resistance to enable 

 t to act, are in the water, the difference must be very 

 material, so much so, indeed, that we can hardly insti- 

 tute any comparison, as we are not acquainted with 

 any one mechanical contrivance which, acting wholly 

 m the water, and equally both ways, as the fin of a 

 fish does, which can impel itself forward. The three 

 efficient fins of this species, the second dorsal, the 

 anal, and the caudal, are all near each other, and they 

 are also powerful for the size of the fish. It seems 

 therefore that in order that a portion of their action 

 may not be lost by throwing the head of the fish into 

 alternate vibrations, a greater power of " holding on" 

 is necessary ; and thus these branched appendages 

 may produce that steadiness of the body which is 

 essential to the proper action of the fins. When we 

 examine (he lateral appearance, we find that the 

 second dorsal and the anal extend forward nearly to 

 the centre of gravity, and that the long spine answer- 

 ing to the first dorsal, and the projecting and fringed 

 part of the abdomen, arc nearly on the same line. 

 The dorsal spine is connected with the bones of the 

 head, and the fringe at the end of the abdomen is 

 connected with the lateral bones of the cavity of the 

 body, which are connected with the scapular bones. 



It will readily be seen that, while the spine and the 

 fringes prevent lateral motion at the line of which 

 they form the terminations, the stiffness produced by 

 the connections of bones must assist in keeping the 

 anterior part of the fish in the line of its career 

 steadily, while the lateral motions of the tail impel it 

 forwards. Thus, by a careful examination of the parts, 

 and a due consideration of the way in which, according 

 to the known doctrines of motion, the one can react 

 while the other acts, we may arrive at some under- 

 standing of the use even of those parts which at first 

 sight appear to be redundant and even absurd. 



The whole of this genus, and indeed, generally 

 speaking, the whole of the order to which it belongs, 

 are inhabitants only of the warmer seas ; few or none 

 of them are, from the form of the rnouth, fitted for 

 existing upon other fishes ; and their structure is, in 

 general, not such as that they can find their food in 

 substances floating on the surface. It does not appear 

 that the present genus has much of a pelngic habit; 

 they do not range the depths of the ocean, but are 

 found near the rocks, especially the coral reefs, which, 

 even after the little creatures which formed them are 

 gone, appear to abound more in living productions, 

 both vegetable and animal, than most other rocks. 

 Some of the fishes of this order (which appear to 

 be among the grand destroyers of the surplus of 

 small life on these reefs), arc fitted for cutting off, 

 with their trenchant teeth, the fronds of the fuci, while 

 others appear to be more fitted for breaking the crusts 

 and shells of the smaller Crustacea, the young of which 

 in particular are found in myriads among the sea- 

 weed on these reefs. Their economy in the general 

 system of nature will, however, come better under the 

 article on PLECTOGNATHES. 



BALM. A well-known medicinal herb, the 

 Melissa officinalis of botanists. Linnaean class and 

 order, Didynamia gyninospernria ; natural order, 

 Labiate?. Generic character : calyx upper lip flat, a 

 li'tle reflexcd, three-toothed, the lower lip two-parted : 



