THE GENUS FIEEASFER. 66 



is brought forward so as to be under the throat. Dr. Giinther divides the family into five groups 

 of genera. 



The first group, distinguished by possessing ventral fins, includes the genus Lucifuga, which 

 inhabits subterranean fresh waters in Cuba. The eye is either absent or imperfectly developed, and 

 always covered by skin. The air-bladder is remarkable for being fixed to the base of the skull. 

 There are no appendages representing the pancreas developed at the pyloric end of the stomach. 

 The genus Xiphogadus has the body naked. There is a pair of canine teeth developed at the 

 corners of the mouth in both the upper and lower jaws. There is but one species, which is confined 

 to the East Indies. One remarkable circumstance about this small group of fishes may be noticed 

 in the fact that the genera are chiefly met with in the neighbourhood of islands, though one or two 

 reach the Arctic regions, the Mediterranean Sea, and the San Francisco coast. 



The second group, termed Ophidiina, is represented in British seas by Opltidium barbatum, 

 which, though almost confined to the Mediterranean, occasionally comes to the British coast. It is 

 plentiful in the Adriatic, and reaches a length of nine inches. Its flavour is coarse. The ventral fins 

 are here reduced to bifid filaments, which are placed under the lower jaw in the position of barbels. 

 There are two small bones directed downward from the first vertebra, which are connected with a large 

 crescent-shaped bone, placed between the processes of the fourth vertebra, and this bone fits into the 

 anterior end of the air-bjadder. The air-bladder varies in its characters in the other species of the 

 genus. In one from Brazil the anterior bone is replaced by cartilage ; but it is usually absent. The 

 body of the Bearded Ophidium is flesh-coloured, but the edges of the long narrow dorsal and anal 

 fins, which meet posteriorly, are margined with black. 



The third group, called Fierasferina, includes only two genera, both characterised by entire 

 absence of the ventral fins, and by having the vent under the throat. The genus Fierasfer has 

 the body naked, relatively long, with a tapering tail. The dorsal and anal fins extend throughout its 

 length, and there is no separate caudal fin, for the tail tapers to a point. There are four gills. An 

 air-bladder exists in all the species, but there are no pancreatic appendages to the intestine. Nine 

 species are described by Dr. Giinther ; they are mostly found in the Malay seas, as at Ceram, Banda, 

 Aniboyna, Fiji Islands, and New Ireland. The species are mostly small. The Fierasfer dentatus, 

 met with on the coast of Ireland and Scotland, which reaches a length of neai'ly a foot, is about the 

 largest. It is a rare fish, and is chiefly known from the observations made on a few stray specimens. 

 The head is small, about one-ninth of the length of the body. At each corner of both upper and 

 lower jaws a large tooth occurs, which somewhat suggests the idea of a serpent's fang. The 

 nostrils are very large, transverse, oval apertures, just in front of the centre of the eye. The 

 operculum is strongly radiated. In a specimen eleven inches long the vent was one inch and three- 

 tenths behind the extremity of the lower jaw, that is to say, immediately behind the head. There 

 are in this species eighty-eight vertebra?. These fishes prefer sandy ground, on which they lie still 

 for a large part of the day with the body in a curved position. Sir John Richardson describes, 

 from Tasmania and the Australian seas, a species (Fierasfer /wm?i) which has ninety-nine vertebrae, 

 and the head relatively a little longer than in the British species. This species has the remark- 

 able habit of penetrating into the respiratory cavities of the Holothurians, commonly called 

 Sea Cucumbers, and it similarly finds its way into the bodies of Star-fishes, but the nature of this 

 strange relationship between animals so unlike in their habits is at present unknown, and though 

 the fish is probably seeking food, the instinct is so remarkable that the history of its development 

 is looked forward to with interest. The second genus, Encheliophis, is distinguished by having 

 the pectoral fins as well as the ventral fins entirely absent. The air-bladder hei-e possesses a muscular 

 apparatus by which its anterior part may be dilated. The species, four inches long, is found in the 

 Philippine Islands. 



The fourth group of Ophidioid fishes, named from its typical genus Ammodytina, also wants the 

 ventral fins, but has the vent distant from the head, and consequently the anal fin is absent from 

 the anterior part of the body. These fishes, in British seas, are known as Sand Eels and Launces. 

 There are only two genera, Ammodytes, which is met with on the temperate coasts of the Atlantic, 

 in the Mediterranean, and the shores of California, and the genus Bleekeria, which is only known from 

 Madras. Ammodytes lanceolatus is the species commonly known in England as the Sand Eel, or 

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