250 JOURNAL OF CONCHOLOGY, VOL. 16, NO. 8, JANUARY, I922. 



With : — Limax arboriim, Agrioliinax agrestis, Vitrina pellucida, 

 Hyalinia crystallina, H. cellaria, H. 7iitidula, H. pura, Euconulus 

 fulvus, Arion ater, A. subfuscus, A. minimus. A. hortensis, Punctum 

 pygvKziDit, Pyramidula rotundata, Hygromia hispida, Acanthinula 

 aculeata, Helix nemoralis, Etta obscu?a, Cochlicopa lubrica, Pirostoina 

 bidentata, Laiiria cylindracea, Carychium fjiinimuin, and in very damp 

 places, where pools of water usually stand, Agrioliinax IcBvis and 

 Liinncea triincahila. 



Here also is the true position of Cyclostoina elegans, but so far 

 careful search has failed to reveal it within the limits of the district, 

 though it occurs frequently in this type of woodland on exactly similar 

 soil just outside them. Here some unknown factor is evidently at 

 work, as the same applies to the two Xerophiles, C. caperata and C. 

 gigaxii, which become far more numerous just to the north of the 

 district. 



§ 2. a. Beech Wood. 



Of Beech Woods there is but one in the district, a large wood of 

 magnificent trees, purely Beech, lying on a steep slope arising from 

 the river and forming one of the " beauty spots " of the neighbour- 

 hood. The trees are finely grown, and form the dense canopy 

 peculiar to a typical Beech wood. The soil is a deep moist calcare- 

 ous clay, clothed with Dog's Mercury [Afenierialis perennis) to the 

 almost complete exclusion of every other plant, while fungi abound 

 on fallen trees and decaying trunks. This wood has probably been 

 planted out a long time ago, as it seems to be unique. 



Dominant : — Limax arboru/n, L. maximus., zx\di Arion subfuscus. 



Associated with : — Vitrina pelhicida, Hyalinia crystallina., H. cel- 

 laria, H. alliaria, H. nitidula, H. pura, Eticonulus fulvus, Arion 

 minimus, A. hortensis, Puucttnn pygniaum, Pyramidtda rotundata, 

 Hygromia hispida, Aca?ithinula aculeata, Val Ionia costata, Helicigona 

 arbustorum, Ena obscura, Cochlicopa lubrica, Lauria cylindracea, 

 Marpessa laminata, Pirostoma bidentata, and Carychium minimum. 



List of Moi.lusca occurring in the Oundle District. 



In all ninety-five species. 



Limax maximus, * L. fiavus, L. arborum, Agriolimax agrestis, A. 

 IcBvis, "^iMilax sowerhyi, Vitrina pellucida, Hyalinia crystallina, H. 

 cellaria, H. helvetica, H. alliaria, LI. nitidula, H. pura, H radiatula, 

 Zonitoides nitidus, Z. excavatus, Eticonulus Julvus, Arion ater, A. 

 subfuscus, A. minimus, A. hortensis, A. circumsciiptus, Punctum 



* Occurring in " arlificial " habitats, i.e., due to human agency, such as gardens and stone 

 walls. 



