KKN!1>AI.I : IIIK MOI.I.nSfA OF OTTN'Dl.K. 24I 



'I'VPES OK HAIilTAl IN TIIK OUNDl.li DISTRICT. 



A.— Type of Dry Grasslands. 



§ I. Calcareous Pasture. 



>^ 2. Non-Calcareous Pasture. 



Sub-sectioti : Subterratieaii. 



B.^Type of Wet Grasslands. 



v:; I . Marsh. 



S 2. Hard- Water Ponds. 



S 3. Soft-Water Ponds. 



^ 4. Soft- Water River and Streai/is. 



C. — Type of Woodlands. 



^ I. Alder-Willo7v Woodland. 



A. Osier Beds. 



% 2. Ash-Oak Woodla?td. 



A. Beec/i JVoods. 



A.— Dry Grasslands. 



§ T. Calcareous Pasture. 



In what was originally Forest there can of course be no absolutely 

 natural calcareous pasture, such as that of the Chalk Downs, or the 

 grassy uplands of a ]\Iountain Limestone region, but there is here a 

 very large acreage of permanent pasture land, much of which has 

 never been broken by the plough. If the land went out of use it 

 would revert in due course to Scrub and then to Woodland, but in its 

 present state it may be regarded as a permanent development of dry 

 calcareous pasture and shows the molluscan association typical of 

 such a habitat. 



Characteristic species : — Helicella itala, Pupilla niuscoru?n, Vertigo 

 pygnuea. 



Dominant species : — Helix neinoralis ; associated with Agriolimax 

 agrestis, Pundum pygmceum, Helicella virgata, Theba cantiana, 

 Hygroniia hispida, H striolata, and Vallonia excetifrica. 



H. itala is one of the most abundant shells in the district, and 

 V. pygnicea occurs practically everywhere in this type of habitat. 

 Occasionally Candidula gigaxii finds a place in the association, but 

 C. caperata is extremely rare, only an occasional small colony appear- 

 ing. When the habitat is affected by the presence of thickets and 

 small copses with their abundant vegetation, i.e., when it is practically 

 Scrub, the following species can be added to the association : — Limax 

 maxifnus, Arion ater, A. hortensis, Helicigona arbustorufn, Helix 

 aspersa, and H. hortensis. 



