THE EELS AND THEIR ALLIES 2819 



species, are distributed over all tropical and temperate seas, and a few ascend tidal 

 rivers. The majority of them are armed with formidable teeth which frequently 

 alter considerably with age adapted for seizing the fish on which they feed. 

 " Large specimens thus armed," writes Dr. Gunther, "readily attack persons in 

 and out of the water; and as some species attain a length of six or eight feet, they 

 are justly feared by fishermen. The minority of species have obtuse and molar- 

 like teeth, their food consisting chiefly of crustaceans and other hard-shelled ani- 

 mals. Most of the mursenas are beautifully colored and spotted, some in a regular 

 and constant manner, while in others the pattern varies in a most irregular fashion; 

 they have quite the appearance of snakes. ' ' The figured species, which ranges from 

 the Mediterranean to the Indian Ocean and Australia, has the ground color a rich 

 brown, upon which are large yellowish spots, each dotted with small spots of brown. 

 The finless muraenas (Gymnomurana), of which half a dozen species have been 

 described from the Indian and Pacific Oceans, differ in the reduction of the fins to a 

 rudiment near the end of the tail. 



The typical eels, familiar to all in the form of the common European 

 species {Anguilla vulgaris), agree with the great majority of the fam- 

 ily in having the gill openings into the pharynx as wide slits. The skin contains 

 small scales embedded in its substance; the upper jaw does not project beyond the 

 lower; the small teeth are arranged in bands; the narrow external gill openings are 

 situated at the base of the well-developed pectoral fins, and the dorsal fin com- 

 mences at a considerable distance behind the back of the head. Eels, of which there 

 are numerous species, appear to be distributed throughout the fresh waters of the 

 habitable portions of the globe, being reputed to be absent only from those of the 

 Arctic regions, and probably also from cold elevated districts like Turkestan and Tibet. 

 The common European eel is spread over the greater part of Europe and the 

 Mediterranean area although unknown in the Danube and reappears in the 

 United States. The so-called grig, or glat eel, characterized by its lighter color, 

 broader head, and snout, and the more backward position of the front of the dorsal 

 fin, has been generally regarded as a distinct species, although this is not admitted 

 by Day. About a yard is a good size for an eel, although much longer specimens 

 are on record. Few subjects have given rise to more discussion than the mode of 

 propagation of eels, and as this must be noticed in some detail, we take the follow- 

 ing extracts from a paper published a few years ago by the last-named observer. 

 After mentioning the difficulties that took place in the identification of female eels, 

 the author states that when this point was cleared up, naturalists became rather 

 puzzled where to look for the male element, so the idea took root that these fishes 

 might be hermaphrodites. It was observed that in addition to the frill-shaped band 

 forming the undoubted ovaries, there was a second fatty band running along one 

 side of the intestines, in which milt was erroneously stated to have been discovered. 

 In 1873, however,, an organ was discovered in an eel of sixteen inches in length, 

 which was correctly identified with the male element, since which date numerous 

 males, which are generally of smaller size than the females, have been recognized. 

 " For the generation of eels it would seem, so far as we are at present aware, that 

 the presence of salt water is a necessity, for it has been observed that when these 



