52 MUR^NID^E, OR EEL-TRIBE. 



inhabit ponds, rivers, and the brackish water at the mouths of 

 rivers. In the autumn they make their way to the sea in vast 

 numbers ; for the purpose, it is believed, of depositing their 

 spawn. Myriads of minute Eels, three or four inches long, are 

 seen in the spring, making their way up rivers, and dispersing 

 into the tributary streams as they proceed ; but whether the 

 parent Eels thus return is uncertain. It is well known that the 

 Eels which inhabit inland lakes and ponds, whence they cannot 

 escape to the sea, are able to breed without this migration ; but 

 it appears that their season is somewhat later, the water in such 

 situations being colder than that of the sea in the early spring. 

 Eels frequently quit the water, in warm, damp nights, and 

 wander over the grass ; either in quest of worms, frogs, or other 

 food ; or in order to change their locality. Many of this family 

 are chiefly marine ; though they occasionally stray into the 

 mouths of rivers : this is the case, for instance, with the Conger ', 

 which is one of the largest of the whole order, sometimes mea- 

 suring six feet in length, and being as thick as a man's leg. 

 The Ophisurus, or Snake Eel (so called from its strong resem- 

 blance to a serpent) of the Mediterranean, attains the same 

 length, but is not so thick. In the genus Murcena, and its allies, 

 the pectoral as well as the ventral fins are wanting ; and the gill- 

 openings are extremely small. This, too, is a Mediterranean fish ; 

 it was much esteemed by the ancients, who kept it carefully in 

 ponds ; and there is a well-known story of a cruel master, who 

 caused his offending slaves to be flung alive into the ponds, to 

 feed the Muraense. The common species grows to the length of 

 three feet or more ; its surface is mottled brown and yellow ; and 

 it is very voracious and ugly. In some of the genera nearly allied 

 to this, the gill-passages unite, so as to open externally by a 

 single orifice on the under side of the neck ; and in several of 

 these, we find the air-bladder almost as completely presenting 

 the characters of a rudimentary lung, as in the Sauroid Fishes 

 ( 588). 



577. The Gymnoti, or Electric Eels ( 540), and their allies, 

 have been separated from the preceding family by some natu- 

 ralists, on account of the less complete inclosure of the gill-covers 



