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clotted blood. Yarrel informs us that " the London market 

 is principally supplied from Holland by Dutch fishermen." 

 The cultivation . of eels and lampreys is now rendered very 

 remunerative in Italy and in some parts of Germany. The 

 average weight of each is from one to three pounds, but they 

 have been known to attain to fifteen pounds' weight. 



THE LAMPREY. 



A member of the Petromyzidce family, constituting the sec- 

 tion cyclostomi of the " Regne Animal," distinguished by an 

 imperfectly developed skeleton and want of pectoral and ven- 

 tral fins, combined with an eel-like form of body. The mouth 

 is circular, consisting of a cartilaginous ring formed by sol- 

 dering together the palatine and mandibular bones. The 

 branchiae, instead of being pectinated, are purse-shaped, and 

 open externally by several apertures. 



THE LAMPREY. Petromyzon marinus. 



The lamprey is supposed to be the lowest of the vertebrate 

 animals. They are usually two feet in length, and the en- 

 graving is a fac-simile of them. Having no swimming-blad- 

 der, and being also without pectoral fins, they usually swim 

 near the bottom ; and, to save themselves from the constant 

 muscular exertion which is necessary to prevent them from 



