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A HISTORY OF SUFFOLK outside. It is an excellent district for collecting animals like Medusae drifted in by the strong tide from the more open sea. Passing westward up the Stour there are large tracts of mud covered by Zostera marina^ in some places as much as a mile wide, left dry at low water, and at a dis- tance looking much like green fields. Dr. Laver of Colchester informed me that many interesting fishes may be caught by trawling over these flats, and possibly some interesting animals may occur in parts I have not been able to examine, as for instance near Wrab Ness. I have spent a good deal of time at Mistley, and have obtained some animals which I have not found elsewhere ; but on the whole it is too far up the estuary to be satisfactory. I have lived many months on the Orwell at Pinmill, and have very often dredged and trawled and collected on the surface and shores in a long series of years. Here also are wide tracts of mud covered by Zostera left dry at low water. In some places the edges of these left dry when the tide is low have yielded a number of rare and interesting animals, several of which I have never found elsewhere, whilst one had not been previously found in England. The character of the deeper water near Pinmill changed remarkably from 1895 to 1902, and furnished an excellent illustration of the effect of changing condition on the animals living at the bottom. At about 1895 and earlier, before extensive dredg- ing operations were carried on to improve the navigation to Ipswich, the water was remarkably clear and the bottom covered by an unusual variety of living animals, some of which I have seldom or never found elsewhere. Later the deposit of mud caused the bottom in 1897 to be covered by tough material built into imperfect tubes by countless numbers of Amphipods, mainly Jassa pulche/Ia. In 1898 and 1899 the bottom was comparatively clean, and still more so in 1900, but still even in 1901, when it had become fairly good, most of the interesting animals which had been displaced had not returned, and the ground was almost completely usurped by vast numbers of Ascidklla aspersa. Since then I have not been able to visit the locality and learn how far the original conditions have been restored. Passing north of Felixstowe are some rocks left dry at low water which, unfortunately, I have examined very imperfectly. The estuary of the Deben is in some respects similar to the Orwell and yet differs materially. I have studied it fairly well all the way to Woodbridge and found in considerable numbers several animals which are rare elsewhere. North of the Deben the conditions begin to change, and the amount of coarse moving gravel increases much and is most remarkable near the mouth of the Aide, very properly called ' Shingle Street.' I have studied this estuary to a good way above Aldeburgh, where it must often be under the influence of fresh water. Taken as a whole the animals differ considerably from those in the Orwell and Deben. Passing the mouth of the Aide we come to Ortord Ness and enter the North Sea, where the conditions of the coast differ much from those in the more southern parts of the county. The coast here is more 86