CHAPTER XXXIX. 



THE LAMPREY. 



THERE are only three species of the Lamprey family likely to be met with 

 by the ordinary student of British fresh-water fish or the angler- 

 naturalist ; and these are the sea lamprey, or Petromyzon marinus ; the 

 lampern, or river lamprey, Petromyzon fluviatilis ; and Planer's lamprey, 

 or Petromyzon Planeri. There is another species, called the sand pride, 

 or P. Iranchialis, to which I shall also advert, but it is of little interest 

 to the practical fisherman. I shall take these, and briefly consider them 

 seriatim. 



P. mwrinus. The generic characteristics of the Petromyzon family is 

 as follows : Body smooth, elongated, cylindrical, like the eel ; rounded 

 head, mouth circular, armed with hard toothlike processes, the lip 

 forming a continuous circle round the mouth ; seven apertures on each 

 side of the neck leading to branchial cells ; pectoral and ventral fins 

 absent, the skin towards the tail extending to form (both above and 

 below the dorsal), anal, and caudal fins. These fishes are of a very low 

 order of organisation amongst vertebrated animals. 



Having no bladder and no pectoral fins, they are all usually found near 

 the bottom, and, in order to support them in a fixed position in running 

 waters, the peculiar shaped mouth, already described, is brought into 

 requisition in a somewhat similar way to the ordinary leather sucker used 

 by boys to fling stones. The fishes attach themselves, indeed, as the 

 name implies, to stones, and thus are enabled by the extraordinary power 

 of suction they possess to preserve their equilibrium in the flowing 

 water. Nor is this peculiar property simply used for the preservation of 

 the fish's position. Sir William Jardine says : " They ascend the rivers 

 to breed about the end of June, and remain until the beginning of 

 August. They are not furnished with any elongation of the jaw afforded 

 to most of our fresh-water fishes te form receiving furrows at this 



