THE LAMPREY. ^ 185 



termed lampreys and lamperns, which form a 

 distinct family (Petromyzidce.) These singular 

 creatures have the lips thick, flexible, and 

 adapted for forming a circular sucker con- 

 tinued around the mouth. The mouth is also 

 circular, and armed with hard tooth-like pro- 

 cesses ; it is usually concealed by the lips, 

 which cover it when not acting as a sucker. 

 On each side of the neck are seven branchial 

 orifices, opening into branchial cells. The 

 respiratory apparatus of the lamprey engaged 

 the attention of sir E. Home, whose observa- 

 tions were published in the Phil. Trans. 1815, 

 p. 257, etc. ; and it would appear that when the 

 lamprey clings to a stone, by means of its 

 sucking mouth, that the water is received in 

 through the orifices on one side, traverses the 

 internal apparatus, and is discharged from the 

 orifices of the opposite side, a regular succession 

 of currents being maintained.* The hinder 

 caudal portion of the body only is furnished 

 with a continuous fin above and below. 



The lamprey, or sea lamprey, (Petromyzon 

 marinuSj) is widely spread in the seas of Europe 

 and America. It exists in the Mediterranean, 

 as well as in the colder latitudes, and is every- 



* See professor Owen's remarks in the Catalogue of the 

 Mus. R. Coll. S. 



