94 PROCEEDINGS OF THE MALACOLOGICAL SOCIETr. 



1. Alluvium, with very few shells ... ... ... 3 feet. 



2. Shelly loam 1 foot. 



3. Gravel, passing under the river. 



Mr. Treacher kindly sent us a sample of the shelly loam, and on 

 washing this we obtained a large number of molluscan remains, 

 representing twelve species, viz. — 



Avion ater (Linn.), abundant. Gochlicopa lubrica (MiilL), 1 example. 



Vallonia pnleheUa (MiiU.), common. Jaminia muscorum (Linn.), 9 examples. 



Zonitoides nitidus (MiilL), 1 example. Succinea elegans (Eisso), 3 examples. 



Hygromia hispida (Linn.), abundant. Limncea pereger (MiilL), 3 examples. 



HeUcella Itala (Linn.), 4 examples. L. palustris (MiilL), 6 examples. 



Helix nemoralis, Linn., 2 examples. Z. truncatula (MiilL), 5 examples. 



We also obtained two small flint flakes. It will be noted at once 

 that no less than eight species are land mollusca, three are aquatic, 

 and one semi-aquatic, whilst numerically the land mollusca predominate. 

 There can be little doubt that we are here dealing with an old land 

 surface, and one that, judging from the abundance of slug granules, 

 was subject to flooding. A change in the level of the river has 

 accelerated the deposition of alluvium, and it now lies buried under 

 3 feet of that material. In all probability it is of some antiquity, and 

 from the occurrence of the flint flakes may well be of Neolithic age. 

 The band formulae of the two individuals of Helix nemoralis are — 

 12 3 4 5 and (1 2 3 4 5). The occurrence of HeUcella Itala is 

 noteworthy, since it is a species that rarely occurs in a Holocene 

 alluvial bed. 



IV. Ilfokd, Essex. 



In 1904 Dr. Frank Corner sent us a quantity of material which had 

 been obtained from a depth of 6 feet during the rebuilding of the 

 bridge over the Koding. From this, by careful washing, a large 

 number of mollusca was obtained. The deposit is undoubtedly newer 

 than the upper peat, and therefore post-E,oman, but nothing was 

 obtained that can in any way enable us to accurately fix its age, 

 although it may well be pre-Norman. Twenty-three species were 

 determined, viz. — 



Avion atev (Linn.), 1 granule. Vivipava vivipava (Linn.), 2 examples. 



Hygvomia hispida (Linn.), 1 example. Valvata piscinalis (MiilL), common. 



Succinea elegans, Risso, 3 examples. Assemania Gvayana, Leach, 1 example. 



Ancylus fiuviatilis, MiilL, 1 example. Nevitina Jluviatilis (Linn.), 5 examples. 



Aevoloxus lacustvis (MiilL), 2 examples. Anodonta cygnea (Linn.), 1 example. 



Limncea pevegev (MiilL), 6 examples. Sphmvium covneum (Linn.), common. 



L. palustvis (MiilL), 4 examples. Pisidium amnicum (Linn.), 1 example. 



Z. truncatula (MiilL), 1 example. P. Senslotvianiiin (Shepp.), 2 valves. 



Planovbis carinatus, MiilL, 2 examples. _P. subtvuncatwn, Malm, 4 valves. 



P. vovtex (Linn.), 1 example. P.pulchellum, Jenyns, 1 valve. 



Bithynia tentaculata (Linn.), common. P.Gasertanum{J^oYi)[^ = cinereum,K\di&T\'^ 

 B. Leachii (Shepp.), 6 examples. 7 valves. 



Of these the most important is Assemania Grayana, which has not 

 hitherto been detected fossil. It is an extremely interesting species, 

 being only known in a living state in England from the estuarine 

 portion of the Thames and Medway, from the River Colne, the 

 Blackwater, the Kentish Stour, the Orwell, the Aide and the Blyth 



