304 Div. 1. VERTEBRATE ANBIALS PISCES. Class 4. 



and their swimming' and flying enemies, they furnish one of the most singular sights in the warm seas. E. exilens, 

 common in the Mediterranean, has the ventral fins long, and in rear of the middle of the body. E. voUtans, com- 

 mon in the Atlantic, has the ventral fins small, and placed further forwards. The latter species sometimes visits 

 the British shores, in single individuals, and even in shoals. They can leap more than two hundred yards in 

 distance, and upwards of twenty feet in height. Their food is understood to be the small floating Mollusca ; and 

 themselves are good eating. 



Next to the Pike family, there is placed a genus of fishes which, though difl^ering but little from 

 that family in other respects, has longer intestines, and two coeca. It will probably give rise to a new- 

 family. This is Mormyrus, having the body compressed, oblong, and scaly ; tail thin at the base, but 

 swelling near the fin ; skin of the head naked, covering the operculum and gill-rays, and leaving no 

 opening for the latter but a vertical fissure, which has led some naturalists to assert that these fishes have 

 no gill-lids, and only one gill-ray, whereas their gill-lids are perfect, and their rays five or six. Their 

 gape is small, and resembles that of the Ant-eater, the angles being formed by the maxillaries. The 

 teeth are small, notched at the extremities, and occupy the intermaxillaries and lower jaw ; and there 

 are bands of small crowded ones on the vomer and tongue. The stomach is a roundish sac, followed 

 by a slender intestine with two coeca, almost always covered with fat ; and the air-bladder is long, large, 

 and simple. They are accounted among the best fishes of the Nile. Two species have a cylindrical 

 muzzle, — the one having a long dorsal, and the other a short one; a third has both the snout and dorsal 

 short; and in a fourth, the forehead forms a protuberance advancing in front of the mouth. There are 

 various other species in the Nile [and probably also in the other African rivers], but they have not 

 been described. 



THE THIRD FAMILY OF THE MALACOPTERYGII ABDOMINALES. 



SiLURiD^ (the Sheat-fish Family.) 



These fishes are distinguished from all the rest of the order by the want of true scales, having only a 

 naked skin, or large bony plates. The intermaxillaries, suspended under the ethmoid, form the margin 

 of the upper jaw ; and the maxillary bones are either simple vestiges, or extended into cirri. The in- 

 testinal canal is large, folded, and without cceca. The air-bladder is large, and adheres to a peculiar 

 apparatus of bones. A strong articulated spine generally forms the first ray of the dorsal and the pec- 

 torals ; and there is sometimes an adipose dorsal behind the other, as in the Salmon family. The fol- 

 lowing are the genera and subgenera : — 



Siluriis. — These form a numerous genus, known by the naked skin, from the mouth being cleft in the 

 end of the muzzle, and from a strong spine in the first ray of the dorsal. This spine is articulated only to 

 the bones of the shoulder ; and the fish can at pleasure lay it flat on the body, or keep it fixed in a per- 

 pendicular direction, in which case it is a formidable weapon, and wounds inflicted by it are understood 

 to be poisoned, which opinion has arisen from tetanus sometimes following the wound, not from poison 

 certainly, but from the ragged nature of the wound itself. 



These fishes have the head depressed ; the intermaxillaries suspended under the ethmoid, and not 

 protractile ; the maxillaries very small, but almost always continued in barbules attached to the lower 

 lip, and also to the nostrils ; the covering of their gills is without sub-operculum or gill-flap ; their air- 

 bladder, strong and heart-shaped, is attached, by its two upper lobes, to a peculiar bony structure, which 

 again is attached to the first vertebra ; the stomach is a fleshy cul-de-sac, having the intestinal canal 

 long and wide, but without coeca. They abound in the rivers of warm countries ; and seeds of plants 

 are found in the stomach of many of their species. The following are the subgenera: — 



Silurus, properly so called, with only a small fin of four rays on the fore part of the back, but with the nnal very 

 long, and approaching very close to the base of the caudal. There is no obvious spine in the dorsal; and the teeth 

 in both jaws, and in the vomer, are like those of a card. 5. glanis, the Sly Silurus, is the largest fresh-water fish 

 of Europe, and the only member of the genus in this quarter of the world. It is smooth, of a greenish black 

 spotted with black above, and yellowish white below ; head large, with six cirri, — two large ones near the nostrils, 

 and four shorter on the lower jaw. It sometimes grows to six feet in length, and weighs three hundred pounds. 

 It is found in the slow-runiung rivers of Central Kurope, and lurks in the mud to watch for its prey. Its flesh is 

 greasy, and is sometimes employed as hog's-lard. [It is named as a British fish, but its visits to these shores are 

 very rare.] Is found in the rivers of Asia and Africa. 



Sehilhiu, have the body vertically compressed, a strong toothed spine in the dorsal, the head small and depressed, 

 the nape suddenly raised, and the eves low down. They have eight cirri, are found in the Nile, and their flesh is 



