Of late years they have been introduced into the Colne in the neighbourhood of Rickmans- worth, where small fish have been taken recently by anglers, thus indicating that this species is breeding in that locality. The late Mr. Panmure Gordon introduced them into the Chess, a tributary of the Colne, whence no doubt some have dropped down into the larger river.
APODES
22. Eel. Anguilla vulgaris, Turt.
The eel fisheries of the Thames used to be of considerable importance, for the little elvers from the sea found their way (and still find it, though in decreasing numbers) up the whole length of the river and its various tributaries. Many of the huge baskets known as eel bucks, which were used in catching these fish, have now been dismantled, and owing to the pollu- tion of the estuary, so it is believed, there are not so many eels as formerly. At the same time the eel is a very common fish in the Thames and the Colne, and is still more plentiful in the Ouse. There is only one species found in British rivers, the difference between eels with broad nose or pointed nose being merely one of sex.
CYCLOSTOMES
23. Lampern. Petromyzon fluviatilis, Linn.
The Thames lampern fisheries were at one time famous, over a million of these fish a year being captured between the estuary and Taplow ; but the modern system of locks and weirs has placed difficulties in the way of their ascent, over-fishing has left its mark, and very few are now taken above the tideway. Now and again a specimen is found in an eel basket.
24. Mud Lamprey (Pride, Blind Lamprey and Fringe-lipped Lamprey). Petromyzon branchialis, Linn.
This curious little fish is still found in the Thames, but not in large quantities. It is to be seen in the spawning season on the shal- lows of clear running brooks flowing into the
main river.
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