THE MTXINE. 189 



rarely emerges from its lurking-place that it is 

 not to be discovered without some search ; 

 Cuvier says, it has been accused of sucking the 

 gills of fishes, because it has, most probably, 

 been confounded with the Petr. planeri. He 

 adds, that it is employed as a bait for hooks. 

 It is for this purpose that the Cornish fishermen 

 use it ; it abounds in the smaller streams of 

 that county; in its habits it is very inactive. 



Along the coasts of Europe, including that of 

 our own island, a singular slender fish, about 

 twelve inches long, is to be found, which Linnaeus 

 regarded as belonging to the class of worms. 

 It is, indeed, one of the lowest in structural orga- 

 nization among the fishes, its vertebral column 

 being merely a soft flexible tube ; it has no 

 eyes, its mouth is circular, with eight feelers or 

 barbules, and there is one hooked tooth on the 

 palate, and two rows of teeth are on each side of 

 th ft- tongue. Its skin, which is smooth, is most 

 copiously lubricated with a slimy gelatinous 

 secretion, poured out from two rows of glands, 

 extending along the under surface. The head 

 is blunt, with only one spiracle connected with 

 the interior of the mouth ; on each side of the 

 body is an orifice, whence proceeds a membra- 

 nous tube, leading to the respiratory apparatus 

 on its own side. This singular fish is called the 



