ICHTHYOLOGY. 



227 



I.opJio- Genus Ammodytes, Linn. Has a thin and elongated 

 branchii. form. The dorsal fin is furnished with articulated rays, 

 ^""'y^^ but is simple for a considerable part of its extent. There 

 is a second fin behind tlie anus, and a third at the end of 

 the tail, which is forked. These three fins are quite dis- 

 tinct, or separate from each other. The snout is point- 

 ed ; the upper jaw susceptible of extension, but the lower 

 is longer than the upper when the latter is not extended. 

 The stomach is angular and fleshy ; there is no swim- 

 ming bladder nor CKca. Only one British species is as 

 yet distinctly known, the Ammodi/tes tobianus (our com- 

 mon launce), a fish about eight or ten inches long, the 

 body somewhat of a square form, but the angles not 

 sharp, and the sides slightly convex. It is very frequent 

 on our sandy coasts. Its back is bluish, the rest rich sil- 

 very. This fish lives on vermes and other marine animals, 

 which it is believed to pursue by burrowing in the sand, 

 from whence it is often dug up at the depth of a foot. It is 

 prized as food, and is considered as an excellent bait for 

 turbot and mackerel. It is the favom-ite prey of the latter 

 fish ; and the porpoise ploughs up the sand at the bottom 

 of the sea with his nose, in the manner of a hog, in search 

 of this species, which has often been foimd in his stomach. 

 It is also sought for by salmon, which have been captured 

 in the sandy bays of Sutherland, by means of a hook 

 baited by a launce, commonly called the sand-eel. 



It is extremely probable that two British species are 

 usually confounded by us under the name of launce.' 



The various genera of fishes with which we have been 

 hitherto engaged, not only possess an osseous or fibrous 

 skeleton, and free and complete jaws, but their branchia; 

 are constantly pectiniform, that is, in the shape of lamina; 

 or combs. We now proceed to others, in which the re- 

 spiratory organs assume another form. 



ORDER v.— LOPHOBRANCHII. 



,7aws complete and free, as in the preceding orders, but 

 the branchiae, instead of being comb-shaped, are divided 

 into little rounded tufts, disposed in pairs along the bran- 

 chial arches. The branchiae have this further peculiarity, 

 that they are entirely enclosed beneath a large operculum, 

 attached all round by a membrane, which jiermits the wa- 

 ter to escape merely through a small hole, and exhibits 

 only vestiges of rays. 



The genera of this order may be distinguished exter- 

 nally by the cuirassed aspect of their bodies, which are 

 strongly plated, very angular, and frequently furnished 

 with spiny projections. The species are meagre creatures, 

 of small size, and very extraordinary aspect. They have 

 scarcely any flesh upon their bones. The intestine is uni- 

 form, and without caeca ; the swimming bladder is thin, 

 but tolerably large in proportion to tlie other parts. The 

 order is almost entirely composed of the old genera Syng- 

 natlius and Pegasus of Linnaeus. 



The genus Syngnathus of the great Swedish naturalist 

 consisted of a rather numerous assemblage of species, dis- 

 tinguished by a tubular muzzle, formed, like that of the 

 FisTULARiDvE, by a prolongation of the ethmoid, vomer, 

 and tympanic bones, of the pre-opercles, sub-opercles, &c. 

 and terminated by a mouth of the ordinary kind, but al- 

 most vertically cleft. The respiratory opening is towards 

 the nape of the neck, and the ventral fins are wanting. The 

 generative system is characterised by this peculiarity, 

 that the eggs slip into, and are hatched in, a kind of sac or 



pocket, formed by a pursing of the skin — in some beneath Lopho- 

 thc belly, in others at the base of the tail. This pouch branchii. 

 opens in due time for the escape of the young. In this *""'^"~' 

 respect, then, these fishes may be said to connect the osse- 

 ous with the cartilaginous kinds, for the eggs arc hatched 

 internally, and the young are produced alive. This fact 

 was observed by Aristotle, and has lately been confirmed 

 (so far, at least, as concerns .S'. acus) by Cavolini. The 

 genus is now subdivided into three minor groups, as fol- 

 lows : — 



\st, Genus Syngnathus properly so called. Body 

 very long, thin, and differing but little in its diameter 

 throughout. Several species occur in all our seas. They 

 differ in the character and mmiber of their fins. 



2rf, Genus Hippocampus, Cuv. Body laterally com- 

 pressed, and obviously higher than at the tail. The sur- 

 face is raised into ridges, its edges are angular and incis- 

 ed, and the hinder parts of the body and tail have the ap- 

 pearance of being divided into segments. The caudal fin 

 is wanting. 



Of this genus several species are found in the European 

 seas, and one or two occur along the British shores. The 

 greater number, however, are exotic. In the dried spe- 

 cimens the head is usually bent at right angles with the 

 body, the thorax curved, and the tail bent inwards. From 

 the peculiar aspect which they exhibit in this condition, 

 they have received the name of sea-horses. The most re- 

 markable species with which we are acquainted is the 

 Hippoeampus fofiatvs of Shaw, or foliated pipe-fish. (See 

 Plate CCCVI. fig. 7.) This rare and very singularly con- 

 structed fish is a native of the Southern Ocean. The 

 specimen described by Shaw was transmitted from New 

 Holland to Sir Joseph Banks. The one here figured 

 was sent to Professor Jameson from Van Diemen's Land. 

 We should not have hesitated to consider this species 

 as synonymous with S. tomiolalus of Lacepede (and the 

 more readily as they seem to be regarded as identical 

 by Cuvier") ; but on comparing it with the figure in the 

 Annales du Mits. we find that the Van Diemen's Land 

 specimen possesses two large appendages on the dorsal 

 outline, not represented by the author of the earlier Hist. 

 Nat. des Poissons. 



3d, Genus Solenostoma, Seb. and Lacep. Differs 

 from Syngnathus chiefly in possessing very large ventrals 

 placed behind the pectorals, and united together and with 

 the body so as to form a kind of apron, which, like the pouch 

 of the genus just named, serves to retain the ova. There 

 is also a dorsal, with few rays, but elevated, and placed 

 near the nape ; another very small fin on the origin of 

 the tail ; and a large pointed caudal. In other respects 

 the genus bears a great resemblance to Hippocampus. 

 There is only a single species known, the Fistularia pa- 

 radoxa of Pallas.-" 



Genus Pegasus, Linn. Projecting muzzle formed 

 by the same pieces as in the preceding genera, but the 

 mouth, instead of being placed at the extremity, is found 

 at the base, and, in its protractile nature, so far resembles 

 that of the sturgeon, although it is composed of the same 

 bones as the mouth of ordinary fishes. 



The body in this genus is cuirassed like that of Hippo- 

 campus and Solenostoma, but the trunk is broad, depress- 

 ed, the branchial opening lateral, and there are two dis- 

 tinct ventral fins behind the pectorals, which are often 

 large and wing-like, and have given rise to the generic 

 name. The dorsal and anal are opposite to each other. 

 The species are chiefly from the Indian seas. See Plate 

 CCCVL fig. 10. 



' See Regne Animal, t. ii. p. 360 ; and Bulletin des Scienets for September 1 824. 

 licgne Animal, t. ii. p. 363. 



S Sficilcgia, viii. iv. 6. 



