302 BRITISH FRESH-WATER FISHES 



Lampreys attain a length of thirty inches and a weight of 

 3 lb. They were esteemed a high delicacy in old times, 

 and are still to be seen in the shops of London fishmongers 

 in spring, but it is to be presumed that they have lost their 

 ancient repute, as I have never seen them served at table. 

 It is probably one of the facts in history that stick most 

 firmly in the memory of schoolboys, that Henry I. of England 

 died after eating too freely of a dish of lampreys. 



The distribution of this fish is a wide one, aided, perhaps, 

 by its habit of attaching itself by the mouth to other fish and 

 to the bottoms of ships and boats. It is found in most parts 

 of Central and Southern Europe, except the Black Sea district, 

 on the west coast of Africa north of the Equator, and on 

 the Atlantic seaboard of America. In England the principal 

 lamprey fishery is in the Severn. 



The Lampern {Petromyzon fluviatilis) 



The lampern bears a general resemblance to the lamprey, 

 but in Britain does not often attain a greater length than fifteen 

 inches, though it grows to the length of nearly two feet in 

 Asiatic waters. It is not mottled like its larger relative, the 

 back being of a uniform tint varying from steel-blue to olive- 

 green ; the sides are yellow, and the belly silvery-white. The 

 fins, which are purplish, seem to be adipose, but really contain 

 soft, branched rays. The eye is relatively larger than in 

 the lamprey, with a golden iris, flecked with dark brown. 

 The mouth is nearly circular, on the same general plan as the 

 lamprey's, but less formidably armed. Within the cartilaginous 

 lip is a fringe of short tentacles, surrounding a row of minute 

 and easily-detached teeth. At the back of the throat is a large 

 plate, armed with eight horny teeth. Two large teeth stand 

 at the forepart of the mouth, and the maxillary plate carries 

 only five very small teeth. There are two teeth on the 

 tongue. 



