43§ 



SOFT-FINNED GROUP. 



Snake-Fishes. 



Parasitic Fish. 



The typical genus Ophidium, constituting, with an allied form, 

 the second subfamily, has the pelvic tins replaced by a pair of barbel- 

 like filaments ; the elongated and compressed body being covered with very 

 minute scales, while the eyes are medium, and the teeth small. The few species of 

 this genus range over the Atlantic and Pacific. In the South American, South 

 African, and Australasian seas there occur three much larger but nearly allied fishes, 

 which have been referred to a second genus (Genypterus), on account of the outer 

 row of teeth in the jaws, as well as those of the single palatine series, containing 

 some enlarged tusks. These fish are of considerable commercial importance, and are 

 known at the Cape as klipvisch, and in New Zealand as Cloudy Bay cod, or ling. 



Some half-score species of very small eel-like fishes, scientifically 

 known as Fierasfer and Encheliophis, and inhabiting the Mediter- 

 ranean, Atlantic, and Indo-Pacific, have an especial interest on account of their 



curious mode of life. They 

 constitute a subfamily, readily 

 characterised by the total 

 absence of pelvic fins and by 

 the vent being situated at the 

 throat ; and are parasitic in 

 other marine animals, fre- 

 quenting the hollows in the 

 bodies of jelly - fish, the 

 breathing-chambers of star- 

 fishes and sea-cucumbers, and 

 sometimes insinuating them- 

 selves between the layers of 

 the mantle of pearl-mussels 

 or other bivalve molluscs. 

 Occasionally they may become 

 embedded in the substance of the shell of the pearl-mussel by the deposition of 

 pearly matter over their bodies ; an instance of this peculiar mode of preservation 

 being shown in the accompanying illustration. 



The third subfamily is represented by the well-known sand-eels or 

 launces — of which a British species (Ammodytes tobianus) is figured 

 in the illustration — so abundant on sandy shores in Europe and North America, 

 as well as by an allied genus from Madras. While agreeing with the preceding 

 group in the want of pelvic fins, they differ in having the vent situated far back 

 in the body ; and are further characterised by the great width of the gill-openings, 

 the gill-membranes of opposite sides not being united. The lower jaw exceeds the 

 upper in length, the dorsal fin occupies nearly the whole length of the back, and 

 the anal is likewise elongated. The figured species, which is by far the commoner 

 on the British coasts, generally measures from 5 to 7 inches in length, whereas the 

 greater sand-eel (A. lanceolatus) may grow to a foot and a half. Sand-eels feed 

 on marine worms and very small fish ; and when buried in the sand are captured 

 in some parts of England by raking the sand with a long-pronged rake ; their 

 chief use being for bait. They are, however, by no means restricted to this kind 



PARASITIC FISH EMBEDDED IN A PEARL-MUSSEL. 



(From Giinther, 1'roc. Zool. Soc., 1886.) 



Sand-Eels. 



