242 PISCES. 



to that of the Lampreys: the tongue also acts like a piston, and the spine 

 of the back is in the form of a cord. The mouth is circular and surrounded 

 with eight cirri $ in its upper margin is a spiracle which communicates with 

 its interior. The body is cylindrical, and furnished behind with a fin that 

 surrounds the tail. There are no vestiges of eyes. The eggs become 

 large. These singular animals pour out such an abundance of mucus through 

 the pores of their lateral line, that the water of the vases in which they are 

 kept seems to be converted into a jelly. They attack and pierce other 

 fishes like the Lampreys. 

 They are subdivided according to the external orifices of their branchiae. 



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