Director: June Chatfield
On 26th. July, 1964, a few members of the Society visited Albury, near Guildford to record land and freshwater mollusca in the National Grid square 51/Ok. Several different habitats were visited, and at the end of the day a list of about forty species was obtained.
The Silent Pool is a large pool at the bottom of the steep scarp slope of the North Downs, and it is supplied by a spring from the edge of the chalk. The water was clear and there was generally little aquatic vegetation, although green filamentous algae and Lemna trisulca (Ivy-leaved duckweed) were abundant in some areas at the surface film. The molluscan fauna of the pool was disappointing, Lymnaea peregra was the only aquatic living species found, although dead shells of Valvata cristata and Pisidium milium occurred in the bottom mud.
Terrestrial molluscs were found under logs, in leaf litter, at the base of trees and on banks in mixed woodland surrounding the Silent Pool and extending almost to the top of the steep scarp slope of the chalk. Species found were:- Pomatias elegans, Carychium tridentatum, Cochlicopa lubrica, Acanthinula aculeata (in leaf litter on the edge of the Silent Pool), Ena obscura, Marpessa laminata, Clausilia bidentata, Cepaea hortensis,
C. nemoralis, Helix aspersa, H. pomatia, Hygromia striolata, H. hispida (on the bank of the Silent Pool), Monacha cantiana (on a grassy bank near a field), Punctum pygmaeum (in leaf litter at the edge of the Silent Pool), Discus rotundatus, Arion intermedius, Arion ater agg., Arion rufus, Vitrea contracta, Oxychilus draparnaldi, 0. cellarius, 0. alliarius, 0. helveticus, Retinella radiatula, R. pura, R. nitidula, Vitrina pellucida, Limax maximus, L. cinereo- niger, Lehmannia marginatus, Agriolimax agrestis agg., A. reticulatus.
New pine wood plantations were seen near the top of the scarp slope, but the molluscs of these woods were not investigated. The recent plantation of pine woods in place of beech and oak woods in Surrey may well reduce the molluscan fauna in considerable areas.
A grassy bank alongside shrubby ground on the slope of the chalk was investigated. The molluscan fauna of this bank was surprisingly small; Cochlicopa lubricella was the only species to be at all frequent, although a few other species were recorded.
Later in the afternoon, after tea, the party visited Newlands Corner and investigated some chalk grassland. This yielded:- Cochlicopa lubricella, Pupilla muscorum, Vallonia excentrica, Hygromia hispida, Helicella caperata and H. virgata.
On a stony pathway surrounded by nettles on the edge of the chalk near Weston Wood, many broken shells were seen, these representing the site of a bird's anvil. The species broken were:- Cepaea hortensis, Arianta arbustorum and Monacha cantiana, in order of abundance.
The day's collecting came to an end with the investigation of an old Gault clay pit at Weston Wood. This pit is gradually being filled with sand from the Albury Sand Pit. It contains two ponds, a small one on the sand which yielded no molluscs, and a larger one on the Gault which yielded many specimens of Lymnaea peregra, but no other species of mollusc. A few interesting fossils were found in the Gault clay. There were three types of ammonite:- Mortoniceras inflatum, Beudanticeras beudanti and a possible Hysteroceras sp.. Other fossils were internal casts of gastropods (indetermined) and fragments of Serpulid worm casts.
The excursion was both a pleasant and successful one. However, due to the hot dry weather, many species were not found, and thus there is plenty of opportunity for further field work at Albury.
NOTE: Arion rufus was determined on dissection of the genitalia.