MALACOPTERYGII APODA. 325 



THE FOURTH ORDER OF BONY FISHES. 



MALACOPTERYGII APODA. 



The fishes in which ventral fins are always wanting, form but one natural family. 

 Mtcranida, or Eel-shaped Fishes, which are lengthened in form, have the skin thick and soft, the 

 scales almost invisible, and but few hones. They have no coeca, but almost all have air-bladders, often 

 singularly shaped. 



The genus Murcena is easily known by small opercular, surrounded by concentric rays buried in the 

 skin, and opening only by a hole at some distance backwards, which arrangement, by protecting the 

 gills, enables these fishes to live long out of the water, [and crawl for some distance over-land, when 

 such a journey is necessary.] Body long and slender, scales visible only on the dried skin, no ventrals 

 or cceca, and the vent far backwards. This extensive genus may be subdivided as follows : — 



Anguilla, known by the pectoral fins, and the gill-openings under them ; stomach a \or\y; cul-de-sac, intestine 

 straight, and a peculiar gland near the middle of the long air-bladder. They are again subdivided : — Anguilla, 

 the true Eels, have the dorsal and caudal meeting at the extremity of the tail, and forming a point, and the dorsal 

 beginning a considerable way behind the pectorals. [They have also a singular pulsatory apparatus for the circu- 

 lation of lymph, situated near the extremity of the tail. They are, strictly speaking, fresh-water fishes.; but they 

 migrate to the sea in the end of the season, bury themselves in the sludge there, and mature their spawn, again 

 ascending the rivers for the purpose of spawning. Like Trout, they are much affected in appearance and quality 

 by the waters which they inhabit. Three species are known as British Eels : — Acutirostrus, the Sharp-nosed Eel ; 

 Latiroslnis, the Broad-nosed Eel ; and Mediorostrus, the Snigg Eel. Eels are delicate fishes, and not found in 

 very high latitudes. In Britain they are most abundant, and best in quality in the pure rivers which rise in the 

 chalk districts.] 



Conger. — Dorsal commencing near or at the pectorals, and upper jaw longest. Tlie Conger is found in most 

 European seas ; and is sometimes from four to six feet long, and as thick as a man's leg. Tlie margins of the 

 dorsal and anal are black, and the lateral line marked with white spots. C. myrus of the Mediterranean is smaller 

 than the Conger, and has whitish spots on the snout and the occiput. In some foreign ones, the dorsal begins 

 before the pectorals. 



Ophisurus, Snake Eels, differ from the former in having a portion of the extremity of the tail without fins, and 

 ending in a pouch like the tail of a Serpent. O. serpens of the Mediterranean is brown above, silvery beneath, 

 has the snout slender and pointed, grows to the length of six feet or more, and is as thick as a man's arm. Some 

 foreign species have the pectorals much smaller, which gives them a little the appearance of the genus, — 



Murtcna, which have no pectorals, very small gill-openings, gill-lids thin, and the rays not easily discernible ; 

 the stomach short.; the air-bladder small, and placed in the upper part of the cavity. Some have one row of sharp 

 teeth in each jaw, among which is, — M. fielena, common in the Mediterranean, and much esteemed by the ancients, 

 who carefully fed it in ponds. The story of Vaedius Pollio, w ho caused his offending slaves to be flung alive into 

 the ponds to feed the Murajnae, is well known. They grow to the length of three feet or more, are mottled brown 

 and yellow, and very voracious and ugly. 



Others have two rows of sharp teeth in each jaw, and one on the vomer ; and others, again, have round or conical 

 teeth, as M. unicola of the Mediterranean, which appears uniforndy brown, though marked with small lines and 

 modellings. Others have two rows of teeth on the vomer, and a single one on the jaws; others, again, have two 

 rows on the jaws, and four, like a pavement, on the vomer; and others still have several rows of card-teeth, as 

 M. saga, with long, round, and pointed jaws, and the tail ending in a very sharp point. 



Sphagebranchus, have the gill-openings near each other below, the fins apparent only near the tail, and the snout 

 long and pointed. Some want pectorals, others have mere vestiges, and others still are totally finless. 



Monopf eras, have the gill-openings united, but with a partition ; the dorsal and anal apparent only from the 

 middle of the tail backwards ; card-teeth on the jaws and palate ; six gill-rays, and only three very small gill-arches. 

 The known species is from the Moluccas, and it is green above and fawn-coloured below. 



.s;vH6rrt«c//H4-.— Gill-opening entirely single, no pectorals, fins fatty, head thick, snout rounded, operculum carti- 

 laginous, with six rays, stomach and anal perfectly straight, and bladder long and narrow. Found in the seas of 

 hot countries. 



Alabes, haye one gill-opening; pectorals well marked, with a disc between them; gill-lids small, with three 

 rays ; teeth pointed ; and intestines as in the last. The well-known species inhabits the Indian Ocean. 



Here should be placed a recently-discovered fish, one of the most singular of the whole class, namely :— 



>Saccopfiari/nx, which can inflate the thorax to a large tube, which terminates in a very long and slender tail, 

 with long upper and under fins meeting at the point. Teeth sharp, mouth opening behind the eyes, which are 

 very near the point of the snout, and gill-opening a small hole under the pectorals. Grows large, and appears to 

 be voracious ; but only a few specimens have been seen floating in the Atlantic, by means of the inflation of the 

 thorax. 



Gymnodis.—GiWs partially covered by membranes, but opening before the pectorals ; vent far forwards ; anal 

 flu occupying the under line of the body, generally to the extremity of the tail, but no dorsal. They admit of 

 subdivision : — 



