A HISTORY OF KENT coast of Kent are much more limited than on the other side of the estuary, but, as far as they go, they show that in summer the density off Ramsgate is about the same as in the North Sea off Lowestoft, and at the Nore about the same as in the Swin, being less than in the Wallet along the coast of Essex, probably because there is a much larger area of shallow water than along the coast of Kent exposed to evaporation in summer. Possibly this is one reason amongst several others why the animals differ materially. The Swale at and above Queenborough is really a strait and not an estuary, and at Queenborough there is only a small difference between the density of high and low water, which plays such an important part in some estuaries. There is only a small decrease in that part ot the Swale near Milton Creek, which is farthest removed from the two openings into the sea. These facts probably explain why, on the whole, the animals found in the Swale differ considerably from those met with in the estuaries of Essex and Suffolk. The Medway up to and beyond Chatham, the Stour up to and beyond Sandwich, and the Thames up to and beyond Erith, are examples of the opposite extreme, the water being in some places almost as salt as the sea when the tide is high, and almost fresh when it is low. These facts have, of course, an immense influence on the distribution of the animals along the north coast of Kent. The Swale near Queenborough. I have dredged and otherwise studied the Swale from its junction with the Medway right up to Milton Creek. One thing which struck me much was the great difference in the number and species of the animals met with in different years. For example, on one occasion I found the bottom almost covered with an enormous number of small mussels, and there were few starfish. The next year these seemed to have invaded the district, and almost or entirely cleared the ground of mussels. One year the beautiful medusa, Chrysaora isosceles (Linn.), was very common, but in other years almost or quite absent. In one year I saw off the Nore more large individuals of Rhizostotna octopus (Linn.) than I ever saw there or anywhere else. The other Medusa? seen more or less frequently were Aurelia aurita (Linn.) and Cyanea captllata (Linn.). Pleurobrachia pileus (Modeer) was common. An unidentified Beroe was also found. The number of Noctiluca mUiaris was sometimes very great. In July 1883 the average number from top to bottom of the water was about 750 per gallon, and occasionally many more. Before it was burned down I used to find on the old pier many specimens of the white, the flesh coloured and the dark brown varieties of Act'moloba dianthus (Ellis), Sabella pavonia (Sav.), and a nemertian worm, probably Serpejitaria fiisca (B.M. Cat. of Worms) which could extend itself in a remarkable manner. From the mud banks I obtained Nereis diver sicolor (Miiller) ; but by far the most interesting polychste 92
