NON-MARINE MOLLUSCA
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Some c o m m e n t s on the recorded species Assiminea grayana Fleming. Morley (1940) reports as follows, 'Several discovered at Aldeburgh in June, 1906; one at the mouth of the R. Orwell in Julv, 1907 by Mayfield, and one in R. Blyth at Blythburgh by A. S. Kennard, F.G.S., before 1908 . . ' We can assume that this was about the time of the beginning of the colonisation of this area by the species; today the population of one drain at the corner of the Aldeburgh Marshes near Slaughden is enormous. Hydrobia neglecta Muus. This species is included in the list with a ?. I collected a large number of Hydrobia spp. on the Aldeburgh Marshes in 1964 and 1965 and several appeared tohave, not only the shape and size as described by Muus, but also the pigmentation of the head and tentacles. Unfortunately I was not able to study the form and shape of the penis which is an important diagnostic character. This species should be searched for on Blythburgh Marshes also. Monacha cartusiana (Müller). For some time the precise status of this species in Suffolk has been in question. From records known to me the only live occurrence was that recorded by Mayfield (1903) who writes, 'There is a flourishing colony of this species on a chalky hedge-bank at Needham Market.' In 1909 he added, 'In a pit at Little Glemham (G.T.R.)'. This observer is Mr. G. T. Rope of Blaxhall, near Wickham Market. Unfortunately there is nothing to show if this latter colony was one of live shells, or whether he only found a few dead shells as has been the case several times in East Anglia. There is also a record of one dead shell at Great Fakenham (Mayfield, 1906). Morley's reference (1940) to ' . . . Glemham Parva (Gr.1903)' may be to the same pit as the one in which Rope found the species. But Green's 1903 list was of Marine Mollusca, so the record is suspect. Mr. R. Fresco-Corbu, of Westcliff-on-Sea, Essex, visited the Needham Market site in the summer of 1968 and reported no trace of the species, not even dead shells. This means that since Mayfield's record (1903) of shells collected by him alive in 1902 no record of live shells of this species has been made in Suffolk for sixty-six years until this species was found by Mr. Stratton in October, 1968, a few miles from Saxmundham. Only one live shell was found and two dead ones, it can be assumed that this colony too may be on the verge of extinction and so preservation of the site is of the utmost importance. Discus rotundatus (Müller). Morley (1940) records, 'Goniodiscus (H) rotundatus, Müll.—Abundant everywhere: Monks Soham'. Our experience was that after careful search in the Aldeburgh Square we found no example of this normally extremely common