OFFER OF A NEW InpDUstRy. 437 
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 Petromyzide 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 
branchiz, instead of being pectinated, are purse-shaped, and 
open externally by several apertures. 
Tue 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 
