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. 
