Occasional Paper No. 20

AN ATLAS OF

TERRESTRIAL

S.J.GREGORY, Northmoor Trust and J.M.CAMPBELL

Published by Oxfordshire Museums in co-operation with the Northmoor Trust

Oxfordshire Museums are a division of the Department of Leisure and Arts Oxfordshire County Council, Oxfordshire Museums Store, Road, , Oxon, OX8 7QG Tel: 01865 300639

 Oxfordshire County Council Oxfordshire Museums Service November 2000

CONTENTS

Page Introduction 1 Recording: Past and Present 1 Habitat Associations 2 Oxfordshire Biological Records Centre 3 Acknowledgements 3 Bibliography 4 Introduction to the maps and accounts 4

General Maps: Main Towns and Natural Areas 5 Calcareous Rocks 5 Woodlands 6 Tetrad Coverage 6

Species Maps (listed alphabetically by , including recent synonyms):

Page Page 15 Hygromia 48 18 Lauria 16 7 Lehmannia 36 Aegopinella 28 34 Arianta 50 41 21 36 46 Milax 32 10 46 Balea 42 Nesovitrea 28 34 Oxychilus 29 Candidula 44 Oxyloma 9 Carychium 8 Perforatella 47 Cecilioides 40 Pomatias 7 Cepaea 51 Punctum 20 Cernuella 45 Pupilla 16 41 Pyramidula 11 Cochlicopa 10 Succinea 9 Cochlodina 40 33 Columella 12 42 Deroceras 37 Trichia 48 Discus 20 Vallonia 17 Ena 19 Vertigo 13 Euconulus 39 Vitrea 27 45 Vitrina 26 50 Zenobiella 47 Helix 52 31

Oxfordshire Museums Service – Biological Records Centre Atlas of Terrestrial Mollusca

INTRODUCTION

The Mollusca are a large and diverse, group of mainly marine . Terrestrial snails and belong to a small part of the Class . There is no real difference between a snail and a . In the latter the shell, so characteristic of snails, is merely reduced in size and usually internal. Most snails and slugs feed on lichens, algae, fungi or dead plant matter. Many will also scavenge corpses if encountered, but only a Glass Snail, Oxychilus draparnaudi, and the Shelled Slugs, Testacella spp., are active predators. These both feed primarily on . A few species, such as the Grey Field Slug, Deroceras reticulatum, and the Garden Snail, Helix aspersa, can be pests of crops and garden plants, but this is the exception.

The Oxfordshire Molluscan fauna is not static. The majority of Oxfordshire’s 91 species of snail and slug live un-noticed in the countryside, many dependent on semi-natural habitats. As human activities put increasing pressure on the countryside some species have become amongst the county’s rarest inhabitants. Other species, such as the Garden Snail have been widely transported by human activities and have been spread well beyond their natural range. This process continues today and recent colonists of the county include the Greenhouse Slug, Lehmannia valentiana, which has now been found outdoors at a few garden centres.

RECORDING: PAST AND PRESENT

The terrestrial Mollusca are one of the most well worked invertebrate groups within Oxfordshire. The visual attractiveness and wide range of colour varieties exhibited by many species made them popular with Victorian collectors. During the 19th century numerous local lists were published, mainly for the Henley, and districts. Towards the end of the century these were collated by Collinge (1891) to give the first full county list complete with details of distribution. The 64 species included most of the county’s known rarities.

In the 1920’s much work was undertaken by two emminent conchologists: the Rev. L.W.Grensted and A.E.Ellis. Four species were added to the county list: the elusive snails Vertigo substriata and V. moulinsiana and the slugs Arion intermedius and . Four additional species were added through taxonomic splitting of species aggregates. For example, Vallonia costata and V. excentrica were distinguished from V. pulchella. Similarly, Candidula gigaxii and Trichia plebeia were also added. This period cumulated with the publication of the of Oxfordshire (VCH) (Grensted 1938) with records collated for 72 species.

Fieldwork undertaken by the Bureau of Population Studies, based at Oxford University, generated many species records from the 1930’s onwards (the ’Wytham Survey’). Further taxonomic splits added Carychium tridentatum, Cochlicopa lubricella, and Vitrea contracta. In the 1960’s and 1970's Dr H.J.M.Bowen undertook surveys on local nature reserves. Largely neglected since the turn of the century, the early 1980’s generated many slug records, including those of M.R.Hughes. The slugs Arion fasciatus, A. silvaticus and Deroceras panormitanum (caruanae) are recorded for the first time.

Since the late 1980's there has been a concerted effort by Dr A.I.Spriggs and the authors to achieve a balanced recording effort across the county within all habitats, including man-made

Oxfordshire Museums Service – Biological Records Centre 1 Atlas of Terrestrial Mollusca (synanthropic) sites, such as churchyards. The presence of five additional snails, Columella aspersa, Euconulus alderi, Perforatella subrufescens, Perforatella rubiginosa and most recently, Hygromia cinctella has been confirmed in the county. Six slugs, all strongly associated with man-made habitats, have also been discovered: Arion lusitanicus, A. flagellus, A. distinctus, Tandonia budapestensis, and Lehmannia valentiana.

To date 91 species have been recorded from Oxfordshire. To the end of October 2000, over 20,000 site-based species records are held on the Oxfordshire Biological Records Centre (OBRC) computerised database (using RECORDER). The majority of these records are post 1990. The collection of data is ongoing.

HABITAT ASSOCIATIONS

Snails tend to be much more numerous on lime-rich soils, due to the requirement of lime for shell building. Slugs are not so dependent on lime and sites with acidic soils can be important for slugs, despite supporting a limited snail fauna. Some species, such as Desmoulin’s Snail (Vertigo moulinsiana) or the Ash-black Slug (Limax cinereoniger), have precise habitat requirements, which makes them good indicators of undisturbed semi-natural habitats. Unfortunately this also makes such species vulnerable to habitat change and degradation. As increasing pressure is put on the countryside for farming, forestry, housing and new roads these have become some of the county’s rarest inhabitants.

Deciduous woodland: This is the natural climax vegetation of southern and has proved the most diverse of the semi-natural habitats. Within Oxfordshire, well over 40 species are regularly encountered within semi-natural ancient deciduous woodland, especially where these lie over lime-rich soils, hold plenty of dead wood and support waterlogged (flushed) areas. Six species, Acicula fusca, Vertigo substriata (wet areas), Ena montana, Limax cinereoniger, Malacolimax tenellus and Perforatella subrufescens are confined to such prime habitat. Other typical woodland inhabitants are Azeca goodalli, Cochlodina laminata, Macrogastra rolphii and to a lesser extent the slugs and Lehmannia marginata.

Calcareous fen and riverside marsh: Wetland is another important semi-natural habitat for slugs and snails within the county, provided they are not cut for hay or too heavily grazed. About 40 species are frequently encountered. Characteristic species include Succinea putris, Oxyloma pfeifferi, Vallonia pulchella, , Deroceras laeve, Euconulus alderi and . Undisturbed wetland, with intact hydrology, is important for the locally scarce Whorl Snails Vertigo antivertigo, V. substriata (if shaded), and V. moulinsiana and the nationally rare Perforatella rubiginosa.

Calcareous Grassland: The lime-rich, free draining soils favour snails that are adapted to the generally dry conditions. Herb-rich short turf grassland supports a specialist snail community characterised by Pupilla muscorum and the common Vallonia excentrica. Two declining species, and are confined to such habitat. , once widespread, is now extinct at its known grassland sites. More frequent species, such as Vertigo pygmaea, Candidula intersecta and C. gigaxii, will also inhabit rougher areas. Where there is a good mosaic of grazed short turf, rough grass and scrub up to 40 species can be

Oxfordshire Museums Service – Biological Records Centre 2 Atlas of Terrestrial Mollusca collected. Open scrub is important for two species, Pomatias elegans and the uncommon Roman Snail Helix pomatia.

Limestone Walls: To a snail, these are nothing more than a poorly vegetated grassland and tend to support similar species. None-the-less old limestone walls, especially if mossy, hold a distinctive fauna. This is characterised by Pyramidula rupestris, Lauria cylindracea. Less frequently, the Tree Snail Balea perversa and the rarities Vertigo pusilla and Helicigona lapicida may be found. A similar species assemblage occurs on roofs tiled with ‘Cotswold slate’ limestone.

Churchyards and Gardens: Man-made (synanthropic) habitats, even in urban areas, can be as diverse as many semi-natural sites. Such sites not only hold a wide range of the more generalist woodland and grassland species, but also a great variety of non-native species, accidentally introduced by human activity. Commonly encountered species include the snails Trichia striolata and Helix aspersa and the slugs Arion ater, A. distinctus, A. hortensis, Tandonia budapestensis and Deroceras panormitanum. Specialist ‘synanthropic’ species, rarely found away from built up areas, are the slugs Arion lusitanicus, A. flagellus, Milax gagates, Tandonia sowerbyi, Boettgerilla pallens, Limax flavus, Lehmannia valentiana, Testacella haliotidea and the carnivorous snail Oxychilus draparnaudi. Because of open public access churchyards have featured prominently in the synanthropic sites examined.

OXFORDSHIRE BIOLOGICAL RECORDS CENTRE

The Oxfordshire Biological Records Centre (OBRC) was set up in 1976 by the County Council Department of Museums Service and co-ordinates biological recording within the current administrative county of Oxfordshire. This was created during the local government reorganisation of 1974 by the amalgamation of ‘old’ Oxfordshire (vice-county 23) with the north-west part of (vc 22).

The uses of the OBRC are manifold and include planning, conservation, education and research. Details about the OBRC. and an annual newsletter are available to interested persons at the following address:

John Campbell Oxon BRC Oxon County Museums Store, Witney Road, Standlake, Oxon, OX8 7QG

ACKNOWLEDGEMENTS

Dr Arthur Spriggs has been a major driving force behind this project, having undertaken much of the fieldwork, offered much advice on fieldwork techniques and provided useful comments on the draft text. Thanks are due to Miss Stella Davies (slugs) and Dr Michael Kerney (snails), of the Conchological Society of Great Britain and Ireland, for advice and prompt identification of difficult or unusual specimens. Mr Charles Elton kindly made the data in the

Oxfordshire Museums Service – Biological Records Centre 3 Atlas of Terrestrial Mollusca Wytham Survey available. Others recorders, notably Dr Keith Alexander, Dr Humphrey Bowen, M.R.Hughes and M.Weideli have contributed their Oxfordshire records to the OBRC.

BIBLIOGRAPHY

Collinge, W.E. (1891) The Land and Freshwater Mollusca of Oxfordshire. The Conchologist, 1: 11-53. Ellis, A.E. (1927) Additional notes on the Mollusca of the Oxford District. Journal of Conchology. 18: 137-138. Grensted. L.W. (1926) Mollusca. In: Walker J.J. (Ed) The Natural History of the Oxford District. Oxford University Press Grensted. L.W. (1938) Mollusca. In: Salzman L.P. (Ed) Victoria County History of Oxfordshire, Oxford University Press. Kerney, M. (1999) Atlas of the Land and Freshwater Molluscs of Britain and Ireland. Harley Books. Kerney, M. & Stubbs, A. (1980) The Conservation of Snails, Slugs and Freshwater Mussels. NCC Whiteaves, J.F. (1857) On the Land and Freshwater Mollusca inhabiting the Neighbourhood of Oxford. Ashmolean Society, Oxford.

INTRODUCTION TO THE MAPS AND SPECIES ACCOUNTS

The species maps have been produced from the computerised data-base held at the O.B.R.C. Species records are site based but the maps indicate the occurrence of a given species within tetrads. Tetrads are 2km by 2km areas defined by the even numbered national grid lines shown on Ordnance Survey maps. The 10km grid squares are shown as numbered solid lines with the tetrads between. Also shown is the course of the which is the approximate pre-1974 county boundary between Oxfordshire (vc.23) and Berkshire (vc.22).

The maps illustrate the occurrence of all native and naturalised species, capable of surviving outdoors. Records are shown for live specimens falling into two time categories. Dead shells of unknown age are listed separately. Only the most recent record for a given tetrad is shown using the symbols below: Records made in or after 1985 Records made prior to 1985 only X Dead and sub-fossil shells of unknown age

Species names follow those used in Kerney (1999), but recent name changes have been put in parentheses to avoid confusion. The presence of each species within the two vice-counties is indicated above the species account. Nationally Notable species (i.e. occurring in 16-100 10km grid squares throughout the British Isles) and those listed in the British Red Data Book (which documents rare and vulnerable species) or in the UK Action Plan (BAP) (which lists species with globally important populations occurring within Britain), are also noted. Species accounts refer to observations in Oxfordshire, unless noted otherwise. VCH refers to the Victoria County History (Grensted 1938). Each species account is followed by a brief summary of the British status.

Oxfordshire Museums Service – Biological Records Centre 4 Atlas of Terrestrial Mollusca

MAIN TOWNS and NATURAL AREAS

2 50 8 Natural Areas are biogeographic zones

6

4 44 characterised by physical factors such 2 

40 as geology and topography and provide 8 

6 a framework for conservation

Banbury 4 2  initiatives across England. Each has a

30 8  unique landscape, rural land use and

6

4  associated fauna and flora. Six Natural

Chipping 55 2 

20 Norton Areas, which clearly correspond to 8 

6 underlying geology (see Map below),  

4 Oxford

2 Witney    occur in Oxfordshire.

10 City

 

8 

6

  SP 63

4 These are:

2 

River Thames

00 64 44: Midland Clay Vales  8 

6 55:  SU 

4

2 

 63: Thames and Avon Vales

90 63



8  64: Midvale Ridge (‘Oxford

6



4 79 Heights’)

2 65



80  65: Chilterns

8 Henley 

6  79: Berkshire and Marlborough  4  2 Downs 2468 2468 2468 2468 2468 2468 20 30 40 50 60 70 80

CALCAREOUS ROCKS

2 The shaded areas indicate where 50 8 limestones and chalk outcrop. These 6 4 correspond closely to the Natural

2

40 Areas of the Cotswolds, the Midvale 

8 

 6  Ridge and the Chilterns. Areas where

4



2  this geology has been masked by more

30 

8  recent drift deposits (e.g. the Chiltern

6



4  Clay Cap) have been omitted.

  2 

20  

8 Oolites, etc 

6    Outcrops of clays occur elsewhere:

4

  

2  Lower Lias to the north and bands of

10

  

8  Oxford, Kimmeridge and Gault clays

6    SP 

4 across the Clay Vales.

2  

00 

 

8 

6 Corallian    SU 

4

2   

90 

  8 

6

 

4 Chalk

2 Clay

 

80 Cap

8  6  4 2

2468 2468 2468 2468 2468 2468 20 30 40 50 60 70 80

Oxfordshire Museums Service – Biological Records Centre 5 Atlas of Terrestrial Mollusca

WOODLANDS

2 All tetrads containing one or more 50 8 woodlands of more than 8 ha in area 6 4 are shown. The approximate extent of 2 40 woodland cover within each tetrad is 8 6 indicated by the size of the symbol. 4 2 The type and quality of the woodland 30 8 varies considerably from conifer 6 4 plantation to blocks of ancient 2 20 deciduous forest. 8 6 4 2 The well-wooded Chilterns are 10 8 apparent. Other well-wooded areas SP 6 4 occur on the Midvale Ridge and in the 2 00 Cotswolds. The Clay Vales and the 8 6 SU 4 are, as a rule, poorly 2 90 wooded. 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

TETRAD COVERAGE The map shows the number of species

2 recorded within each tetrad across 50 8 Oxfordshire. Although some areas are 6 4 better recorded than others it is none 2 40 the less apparent that the richest areas 8 6 correspond to the lime-rich and well- 4 2 wooded areas of the Cotwolds, the 30 8 Midvale Ridge and the Chiltern 6 4 escarpment. 2 20 8 6 4 2 10 8 6 SP 4 2 00 8 6 SU 4 2 90 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 6 Atlas of Terrestrial Mollusca POMATIIDAE Pomatias elegans (Müller 1774) - Round-mouthed Snail

2 50 8 post-1985 vc.22 & vc.23 6 pre-1985 4 2 40 This distinctive burrowing snail can be 8 6 locally common where lime-rich 4 2 friable soils occur over chalk and 30 8 limestones. The species is very 6 4 gregarious with colonies (often 2 20 indicated by abundant dead shells) 8 6 typically found in semi-natural 4 2 10 habitats, such as steep woods or 8 6 scrubby grasslands. Described in the SP 4 2 VCH as “common in calcareous 00 8 districts”. 6 SU 4 2 90 It is locally common wherever friable 8 6 lime-rich soils occur in southern 4 2 England. 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

ACICULIDAE Acicula fusca (Montagu 1803) - Point Snail

2 vc.22 & vc.23 Notable b. 50 8 post-1985 6 pre-1985 4 sub-fossil This small elusive snail inhabits 2 40 ancient deciduous woodland where it 8 6 can be found amongst moss or leaf 4 2 litter and under dead wood or stones. 30 8 Although probably under-recorded it is 6 4 genuinely scarce in the county. Most 2 20 records (usually for single specimens) 8 6 are from the but also 4 2 from Forest and scattered 10 8 sites on the Midvale Ridge. First SP 6 4 recorded from Stow Wood, near 2 00 Oxford, in 1857, the VCH lists three 8 6 SU 4 sites. 2 90 8 6 Nationally, a widespread, but scarce 4 2 and declining species, strongly 80 8 associated with ancient deciduous 6 4 woodland. 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 7 Atlas of Terrestrial Mollusca ELLOBIIDAE Carychium minimum Müller 1774 - Herald Snail

2 50 8 post-1985 vc.22 & vc.23 6 pre-1985 4 2 40 This small species is widespread in 8 6 variety of habitats throughout the 4 2 county, but is easily over-looked. In 30 8 leaf litter, under stones and dead wood, 6 4 beneath loose bark on logs and within 2 20 tussocks it can be numerous. Described 8 6 as “common and widely distributed” in 4 2 10 the VCH, but this also includes records 8 6 for C. tridentatum. SP 4 2 00 8 It is common throughout the British 6 SU 4 Isles. 2 90 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Carychium tridentatum (Risso 1826) - Slender Herald Snail

2 vc.22 & vc.23 50 post-1985 8 6 pre-1985 4 A common and widespread species 2 40 found in similar locations to C. 8 6 minimum. Indeed the two species are 4 2 often found together. They are not 30 8 distinguished in older records and C. 6 4 tridentatum was first recorded in 1952 2 20 at Wytham Wood. 8 6 4 2 Another common species throughout 10 8 the British Isles. 6 SP 4 2 00 8 6 SU 4 2 90 8 6 4 2 80 8 6 4 2

2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 20 30 40 50 60 70 80

Oxfordshire Museums Service – Biological Records Centre 8 Atlas of Terrestrial Mollusca SUCCINEIDAE Succinea putris (Linné 1758) - Large Amber Snail

2 50 8 post-1985 vc.22 & vc.23 6 pre-1985 4 2 40 This, and the following species, can 8 6 sometimes prove difficult to separate 4 2 on external characters. S. putris is 30 8 widespread and associated with marshy 6 4 ground. It does occur at ground level, 2 20 but is most conspicuous high up on 8 6 marginal plants, such as Sweet Grass 4 2 (Glyceria maxima), bordering rivers 10 8 and canals. It may prove to be under- SP 6 4 recorded in the Clay Vales because 2 00 farmland ditches have not been 8 6 adequately surveyed. Described as SU 4 2 “generally distributed” in the VCH. 90 8 6 4 Throughout southern Britain this is a 2 80 8 common species in wetland habitats. 6 4 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxyloma pfeifferi (Rossmässler 1835) - Pfeiffer’s Amber Snail

2 vc.22 & vc.23 50 8 post-1985 6 pre-1985 4 Another widespread wetland species 2 40 often found on vegetation in marshes 8 6 or fens. Specimens have not been 4 2 dissected and atypical specimens may 30 8 have been confused with S.putris (or 6 4 vice versa). First recorded at Cowley 2 20 Marsh, Oxford, in 1853 and referred to 8 6 as “general on marshy ground” in the 4 2 VCH. There is a large proportion of 10 8 older records, possibly reflecting past SP 6 4 confusion with S. putris rather than a 2 00 recent decline. 8 6 SU 4 2 90 Common in a wide variety of wetland 8 6 habitats throughout the British Isles. 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 9 Atlas of Terrestrial Mollusca Azeca goodalli (Férussacc 1821) - Three-toothed Moss Snail

2 50 8 post-1985 vc.22 & vc.23 6 pre-1985 4 2 40 This distinctive snail shows a strong 8 6 preference for ancient deciduous 4 2 woodland on lime rich or acidic soils, 30 8 but avoids the Clay Vales. It can be 6 4 locally widespread, such as in the 2 20 hanging woods of the Evenlode valley, 8 6 but is rarely numerous. It occurs 4 2 amongst moss and beneath stones or 10 8 dead wood. Four sites are given in the SP 6 4 VCH, the earliest from Headington 2 00 Quarry, Oxford, in 1855. 8 6 SU 4 2 90 Outside Oxfordshire this local species 8 6 is scattered across England and Wales, 4 2 typically in wooded areas. 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Cochlicopa lubrica (Müller 1774) - Slippery Moss Snail

2 vc.22 & vc.23 50 8 post-1985 6 pre-1985 4 This is one of the most widely 2 40 recorded species in Oxfordshire. It is 8 6 very common under stones and dead 4 2 wood, amongst moss and leaf-litter or 30 8 within tussocks in most habitats. 6 4 Described as “common and general” in 2 20 the VCH, but this also includes records 8 6 for C. lubricella. 4 2 10 8 This species is equally abundant SP 6 4 throughout much of Britain. 2 00 8 6 SU 4 2 90 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 10 Atlas of Terrestrial Mollusca

Cochlicopa lubricella (Porro 1838)

2 50 8 post-1985 vc.22 & vc.23 6 pre-1985 4 2 40 This species, though widespread, is 8 6 much less common than C. lubrica. It 4 2 is found mainly in woodlands, but also 30 8 inhabits other places including 6 4 churchyards. The two species often 2 20 occur together. The older records do 8 6 not distinguish between them and C. 4 2 lubricella was first recorded in 1952 at 10 8 Wytham Wood. SP 6 4 2 00 Widespread in Britain but much more 8 6 SU 4 localised than C. lubrica. 2 90 8 6 4 2 80 8 6 4 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

PYRAMIDULIDAE Pyramidula rupestris (Draparnaud 1801) - Rock Snail

2 vc.22 & vc.23 50 8 post-1985 6 pre-1985 4 This species can be extremely 2 40 numerous beneath moss and stones on 8 6 limestone walls and on roofs 4 2 constructed from ‘Cotswold slate’. It is 30 8 often abundant in the west of the 6 4 county, but becomes scarcer towards 2 20 the east. It is absent from chalk in 8 6 south, except where limestone has been 4 2 imported. This distribution mirrors that 10 8 given in the VCH i.e. “mainly in oolite SP 6 4 and coral rag areas”. 2 00 8 6 SU 4 This species has a patchy distribution 2 90 in Britain, but is locally common 8 6 where outcrops of limestone coincide 4 2 with a suitably humid climate. 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 11 Atlas of Terrestrial Mollusca VERTIGINIDAE Columella edentula aggregate - Toothless Chrysalis Snail

2 50 8 post-1985 vc.22 & vc.23 6 pre-1985 4 2 40 8 It is difficult to separate the two species of 6 4 Columella in the field and the majority of 2 30 8 records simply refer to the species 6 4 aggregate. The VCH gives four sites and 2 20 comments that it is “surprisingly rare in the 8 6 4 county”. They are small and elusive snails 2 10 and it is only in recent years that an attempt 8 6 has been made to distinguish between them. SP 4 2 00 Recent surveys have shown C. edentula to 8 6 be much more widespread in the county than SU 4 2 C. aspera (see maps below). 90 8 6 4 2 This is in keeping with nation trends, as C. 80 8 edentula is more frequent in lowland areas, 6 4 whilst C. aspera is more characteristic of 2 upland areas and tolerant of acidic soils. 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Columella edentula (Draparnaud 1805) Columella aspera (Martens 1830)

2 2 50 post-1985 50 8 8 post-1985 6 pre-1985 6 pre-1985 4 4 2 2 40 40 8 8 6 6 4 4 2 2 30 30 8 8 6 6 4 4 2 2 20 20 8 8 6 6 4 4 2 2 10 10 8 8 SP 6 6 4 SP 4 2 2 00 00 8 8 SU 6 6 4 SU 4 2 2 90 90 8 8 6 6 4 4 2 2 80 80 8 8 6 6 4 4 2 2 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 20 30 40 50 60 70 80 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880 vc.22 & vc.23: Widespread in a variety of vc.22 & vc.23: Apparently rare and confined damp habitats, including woodland and to areas where acidic soils occur, notably the marsh. Usually amongst moss or leaf litter, Chiltern Hills. but sometimes climbing low vegetation.

Oxfordshire Museums Service – Biological Records Centre 12 Atlas of Terrestrial Mollusca Vertigo pusilla Müller 1774 - Wall Whorl Snail

2 50 8 post-1985 vc.23 only Notable b 6 pre-1985 4 2 40 This tiny species is known from a few 8 6 old shaded moss covered limestone 4 2 walls in the Cotswolds, where it lives 30 8 amongst loose stones and moss. 6 4 Although, easily overlooked it is 2 20 genuinely rare. The VCH lists four 8 6 sites, including one at Woodeaton 4 2 where it was found in 1857 and still 10 8 persists today. It may have declined SP 6 th 4 since the 19 century and has not been 2 00 8 seen in the “Banbury area” since 1855. 6 SU 4 2 90 This widespread but uncommon 8 6 species is associated with rocky 4 2 limestone grassland and old walls, 80 8 mainly in northern England. 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Vertigo antivertigo (Draparnaud 1801) - Marsh Whorl Snail vc.22 & vc.23

2 50 8 post-1985 Another small and elusive snail, found 6 pre-1985 4 amongst rush and sedge litter or moss, 2 40 in fens and riverside marshes. It is 8 6 certainly not common in the county but 4 2 may be overlooked at some sites. The 30 8 VCH gives a single location, near 6 4 Weston-on-the-Green in 1857. 2 20 8 6 This characteristic wetland species is 4 2 frequent in Britain but is declining in 10 8 lowland England. SP 6 4 2 00 8 6 SU 4 2 90 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 13 Atlas of Terrestrial Mollusca

Vertigo substriata (Jeffreys 1833) - Striated Whorl Snail

2 50 8 post-1985 vc.22 & vc.23 6 pre-1985 4 2 40 This rare wetland species is confined to 8 6 a few sites on the Midvale Ridge, 4 2 notably in the Cothill area. It inhabits 30 8 scrubby fen and wet woodland, where 6 4 it occurs amongst moss and sedge 2 20 litter. It is not listed in the VCH. 8 6 4 2 A widespread species found 10 8 throughout Britain but scarce and SP 6 4 declining in the south-east. 2 00 8 6 SU 4 2 90 8 6 4 2 80 8 6 4 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 870 2 4 6 880

Vertigo pygmaea (Draparnaud 1801) - Common Whorl Snail

2 50 8 post-1985 vc.22 & vc.23 6 pre-1985 4 2 40 This is the only widespread Vertigo in 8 6 county, but in common with the other 4 2 species it is elusive and probably 30 8 underrecorded. Often found in small 6 4 numbers amongst moss and grass- 2 20 litter, rarely under dead wood. It 8 6 prefers un-shaded sites ranging from 4 2 wet meadows (where it climbs 10 8 vegetation in winter) to dry calcareous SP 6 4 grassland. A few records are from 2 00 8 churchyards. It is widely recorded in 6 SU 4 the VCH. 2 90 8 6 Frequent in much of Britain and the 4 2 only species of Vertigo not showing a 80 8 marked national decline. 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 14 Atlas of Terrestrial Mollusca

Vertigo moulinsiana (Dupuy 1849) - Des Moulins’ Whorl Snail

2 50 8 post-1985 vc.22 & vc.23 RDB3 UKBAP (p) 6 pre-1985 4 2 40 This county rarity is well known from 8 6 a number of calcareous fens in the 4 2 Cothill area, where it was first 30 8 recorded in 1906. Recorded from 6 4 besides the Thames at Radley in the 2 20 1920’s, but not seen subsequently (now 8 6 a gravel pit). Recently it has been 4 2 recorded from two Thames-side 10 8 marshes further downstream. It is SP 6 4 normally very elusive but climbs tall 2 00 vegetation in autumn where it is more 8 6 SU 4 easily collected. It is not listed in the 2 90 VCH. 8 6 4 2 This rare species is known from fens 80 8 and riverside marshes in southern 6 4 England. It is scarce throughout 2 and legally protected. 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

CHONDRINIDAE Abida secale (Draparnaud 1801) - Large Chrysalis Snail

2 50 post-1985 8 vc.22 & vc.23 Notable b 6 pre-1985 4 2 40 This species remains frequent on the 8 6 short turf chalk grassland of the 4 2 Chiltern Hills, where it was described 30 8 as “local” in the VCH. It is usually 6 4 found amongst grass-litter or under 2 20 stones, occasionally at woodland 8 6 edges. There is an outlying population 4 2 on Whitehorse Hill, but further 10 8 searches of the Berkshire Downs have 6 SP 4 failed to find additional sites. The 2 00 8 species has long disappeared from 6 SU 4 outlying sites on the Cotswold and 2 90 Midvale Ridge limestones and seems 8 6 to be declining in the Chilterns. 4 2 80 8 An uncommon species restricted to a 6 4 few chalk and limestone areas in 2 southern England (where it is 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 870 2 4 6 880 declining) and the Pennines.

Oxfordshire Museums Service – Biological Records Centre 15 Atlas of Terrestrial Mollusca PUPILLIDAE Pupilla muscorum (Linné 1758) - Moss Chrysalis Snail

2 50 8 post-1985 vc.22 & vc.23 6 pre-1985 4 2 40 This small species is widespread in the 8 6 county but is only common on the 4 2 Chiltern chalk. It is typically found in 30 8 semi-natural short-turf grassland, 6 4 including those on prehistoric 2 20 earthworks, where it occurs amongst 8 6 grass-litter and under stones. 4 2 Occasionally it can be found on old 10 8 limestone walls, including a few within SP 6 4 churchyards. Described as “common 2 00 and general” in the VCH, it is possible 8 6 SU 4 that this snail has undergone a decline 2 90 in recent years. 8 6 4 2 A widespread species found on lime- 80 8 rich soils throughout Britain, especially 6 4 on the chalk and limestone in the 2 south-east, but declining in some areas. 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Lauria cylindracea (da Costa 1778) - Common Chrysalis Snail

2 50 post-1985 8 6 pre-1985 4 vc.22 & vc.23 2 40 8 6 In gardens and churchyards this 4 2 common species can be numerous, 30 8 especially on stone walls or even roofs. 6 4 It can also be found under loose bark 2 20 on trees, such as willow pollards, or 8 6 less commonly amongst leaf-litter in 4 2 grasslands, fens or woodlands on lime 10 8 rich soils. Given as “common and 6 SP 4 general” in the VCH. 2 00 8 6 SU Throughout the British Isles this is 4 2 90 common in a variety of typically dry 8 6 habitats. 4 2 80 8 6 4 2

2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 20 30 40 50 60 70 80

Oxfordshire Museums Service – Biological Records Centre 16 Atlas of Terrestrial Mollusca Vallonia costata (Müller 1774) - Ribbed Grass Snail

2 50 8 post-1985 vc.22 & vc.23 6 pre-1985 4 2 40 This, the commonest Vallonia in 8 6 Oxfordshire, is typically found in dry 4 2 open locations, such as calcareous 30 8 grassland, gardens and churchyards. It 6 4 can be found amongst moss, under 2 20 stones and dead wood and often on 8 6 walls. The three species of Vallonia are 4 2 not always separated in older records, 10 8 but the VCH describes this species as SP 6 4 “frequent about Oxford”. 2 00 8 6 SU 4 On the lime-rich soils of south-eastern 2 90 England this is a common species. 8 6 4 2 80 8 6 4 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Vallonia pulchella (Müller 1774) - Beautiful Grass Snail

2 vc.22 & vc.23 50 8 post-1985 6 pre-1985 4 This can be a common snail on the 2 40 Thames flood plain, as is apparent 8 6 from map. It occurs amongst moss and 4 2 within tussocks on damp meadows and 30 8 dead shells can be often found among 6 4 flood debris. It is local elsewhere in the 2 20 county, mainly associated with river 8 6 valleys. Some of the older records may 4 2 refer to V. excentrica, as the two were 10 8 not always separated. The VCH SP 6 4 regarded this as “the least common of 2 00 8 the three species”. 6 SU 4 2 90 In south-eastern England this is a 8 6 frequent inhabitant of damp meadows 4 2 and marshes. 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 17 Atlas of Terrestrial Mollusca

Vallonia excentrica Sterki 1892 - Eccentric Grass Snail

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 A widespread species inhabiting 8 6 similar dry sites to V. costata, but it is 4 2 less frequently encountered. In 30 8 calcareous grassland it is typically 6 4 found with P. muscorum, but it also 2 20 inhabits road verges and lawns. 8 6 Recorded as “common about Oxford 4 2 and probably general” in the VCH. 10 8 Some of the older records for V. 6 SP 4 pulchella may refer to this species. 2 00 8 6 SU Common throughout south-eastern 4 2 90 England, especially on lime-rich soils. 8 6 4 2 80 8 6 4 2

2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 20 30 40 50 60 70 80

Acanthinula aculeata (Müller 1774) - Prickly Snail

2 vc.22 & vc.23 50 8 post-1985 6 pre-1985 4 This small, but very distinctive, snail is 2 40 probably common in deciduous 8 6 woodland and hedge-banks throughout 4 2 much of the county. However, it is 30 8 rather elusive and is typically well 6 4 concealed amongst leaf-litter or within 2 20 crevices on the underside of dead wood 8 6 or stones. The VCH considered it 4 2 “general but not common”. 10 8 SP 6 4 Throughout the British Isles this is a 2 00 8 common species. 6 SU 4 2 90 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 18 Atlas of Terrestrial Mollusca ENIDAE Ena montana (Draparnaud 1801) - Mountain Bulin

2 50 8 post-1985 vc.23 only RDB3 UKBAP (c) 6 pre-1985 4 sub-fossil 2 40 This rare snail inhabits ancient 8 6 deciduous woodlands on lime rich 4 2 soils, often on stony slopes. Restricted 30 8 colonies occur on the Chiltern 6 4 escarpment (where it was widely 2 20 recorded in the VCH) and the 8 6 Evenlode catchment in the Cotswolds. 4 2 In the latter area it was apparently 10 8 overlooked until recent decades. It is SP 6 4 normally very elusive, hiding amongst 2 00 moss and leaf litter, but in wet weather 8 6 SU 4 it readily climbs smooth barked trees, 2 90 such as beech or ash, and becomes 8 6 highly visible. There is no evidence of 4 2 a local decline. 80 8 6 4 This is a nationally rare and declining 2 ancient woodland species patchily 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880 distributed across southern England.

Ena obscura (Müller 1774) - Lesser Bulin

2 vc.22 & vc.23 50 post-1985 8 6 pre-1985 4 This species can be found in small 2 40 numbers within woodlands, shady 8 6 gardens and churchyards on lime-rich 4 2 soils throughout the county. It usually 30 8 occurs amongst leaf-litter or under 6 4 dead wood, but sometimes frequents 2 20 old stone walls and like E .montana, 8 6 will readily climb tree trunks in wet 4 2 weather. Described in the VCH as 10 8 “fairly common”. 6 SP 4 2 00 Outside Oxfordshire this species is 8 6 SU common in shady habitats on lime-rich 4 2 soils throughout England and Wales. 90 8 6 4 2 80 8 6 4 2

2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 20 30 40 50 60 70 80

Oxfordshire Museums Service – Biological Records Centre 19 Atlas of Terrestrial Mollusca ENDODONITIDAE Punctum pygmaeum (Draparnaud 1801) - Dwarf Snail

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 This minute species has proved elusive 8 6 and is probably underrecorded. It is 4 2 certainly widespread in the county and 30 8 found in a variety of habitats, such as 6 4 woodlands, grasslands and 2 20 churchyards. Typically found amongst 8 6 moss and leaf litter or within tussocks. 4 2 It is widely recorded in the VCH. 10 8 6 SP 4 A common species throughout the 2 00 British Isles, especially in wooded 8 6 SU areas. 4 2 90 8 6 4 2 80 8 6 4 2

2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 20 30 40 50 60 70 80

Discus rotundatus (Müller 1774) - Rounded Snail

2 vc.22 & vc.23 50 8 post-1985 6 pre-1985 4 Within Oxfordshire this is the most 2 40 commonly recorded snail. It is readily 8 6 found under stones and dead wood, 4 2 often in large numbers, in almost every 30 8 habitat. It should be present in all 6 4 tetrads. The VCH describes it as 2 20 “common and general”. 8 6 4 2 This species is abundant and 10 8 ubiquitous throughout Britain. SP 6 4 2 00 8 6 SU 4 2 90 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 20 Atlas of Terrestrial Mollusca : Roundback Slugs Arion ater (Linné 1758) - Great Black Slug

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 Varying in colour from cream, orange, 8 6 reddish, brown to jet black this is the 4 2 largest of the roundback slugs. A 30 8 familiar sight in many urban areas, 6 4 normally lurking amongst stones and 2 20 general debris, but following rain 8 6 specimens can be conspicuous in the 4 2 open. Although less frequent in rural 10 8 areas woodlands and grasslands are SP 6 4 also inhabited. Dissection has shown 2 00 both forms, ‘A. ater’ and ‘A. rufus’ to 8 6 SU 4 occur in county, but their relative 2 90 distributions are not known and all 8 6 records have been combined. Recorded 4 2 in the VCH as “abundant and general”. 80 8 6 4 This species is common throughout the 2 British Isles in a wide variety of 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880 habitats.

Arion lusitanicus Mabille 1868 - Lusitanian Slug

2 vc.23 only 50 post-1985 8 6 pre-1985 4 A recent addition to the county list, 2 40 discovered by chance in 1993 8 6 following dissection of an ‘A. ater’ 4 2 specimen. It has been found beneath 30 8 stones, and amongst debris, in a 6 4 churchyard in the east of the county, 2 20 where it is probably a modern 8 6 accidental introduction. All specimens 4 2 have been orange/brown in colour. It 10 8 may be overlooked at other similar 6 SP 4 sites and some records for A. ater may 2 00 8 actually refer to this species. 6 SU 4 2 90 Most old records for this species refer 8 6 to A. flagellus. However, it has been 4 2 shown to be frequent in south-western 80 8 England, with isolated records, 6 4 typically in gardens, occurring 2 elsewhere. 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 21 Atlas of Terrestrial Mollusca

Arion flagellus Collinge 1893 - Durham Slug

2 50 8 post-1985 vc.23 only 6 pre-1985 4 2 40 This large slug was also added to the 8 6 county list in 1993 and is probably 4 2 another modern introduction into the 30 8 county. Specimens are typically bluish- 6 4 green in colour, but are only reliably 2 20 separated from A. ater by dissection. 8 6 The few records are all from 4 2 churchyards. It is may prove to be 10 8 under-recorded and may also be SP 6 4 increasing its range across the county. 2 00 8 6 SU 4 Beyond Oxfordshire, this species is 2 90 widespread, but is most common in 8 6 western areas. Until recently it had 4 2 been misidentified as A. lusitanicus. 80 8 6 4 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Arion subfuscus (Draparnaud 1805) - Dusky Slug

2 vc.22 & vc.23 50 post-1985 8 6 pre-1985 4 Throughout the county this is a 2 40 common species. It is most numerous 8 6 in rural sites, such as woodlands and 4 2 hedge banks, where it can is readily 30 8 found under stones and dead wood. It 6 4 also occurs in churchyards and 2 20 gardens. Recorded as “plentiful and 8 6 general” in the VCH. 4 2 10 8 Throughout many habitats in Britain SP 6 4 this is a common species. 2 00 8 6 SU 4 2 90 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 22 Atlas of Terrestrial Mollusca aggregate - Bourguignat’s Slug

2 50 8 vc.22 & vc.23 6 4 2 40 The map (left) includes all records for 8 6 Arion circumscriptus, A. silvaticus and 4 2 A. fasciatus. The three species can be 30 8 difficult to separate in the field and 6 4 prior to the 1980’s all records within 2 20 Oxfordshire were given for the species 8 6 aggregate. This is given as “common 4 2 and general” in the VCH. The 10 8 distribution of the individual species SP 6 4 within the county remains poorly 2 00 known as can be seen from the maps 8 6 below. SU 4 2 90 8 6 4 2 80 8 6 4 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Arion circumscriptus Johnston 1828

2 50 8 vc.22 & vc.23 6 4 2 40 This may prove to be the commonest 8 6 of the three species within the county. 4 2 Records are mainly from woodlands, 30 8 but also meadows and churchyards. It 6 4 is usually found under stones or dead 2 20 wood. 8 6 4 2 In lowland habitats throughout the 10 8 British Isles this is a frequent species. 6 SP 4 2 00 8 6 SU 4 2 90 8 6 4 2 80 8 6 4 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 23 Atlas of Terrestrial Mollusca

Arion silvaticus Lohmander 1937

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 This slug, with pale silvery flanks, is 8 6 perhaps the easiest of the aggregate to 4 2 identify in the field and consequently 30 8 tends to be the more often noted. The 6 4 majority of the records are from 2 20 deciduous woodland and the mapped 8 6 records strongly correspond with well- 4 2 wooded areas, such as the Chiltern 10 8 Hills and the Cotswolds. SP 6 4 2 00 Throughout the British Isles this is a 8 6 SU 4 frequent slug inhabiting most habitats. 2 90 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Arion fasciatus (Nilsson 1823)

2 50 8 post-1985 vc.22 & vc.23 6 pre-1985 4 2 40 Of the three species this seems to be 8 6 the rarest within the county. Many of 4 2 the records are from disturbed sites 30 8 such as churchyards. About a third of 6 4 the records have confirmed by 2 20 dissection. 8 6 4 2 It is frequent throughout northern 10 8 England and , especially in SP 6 4 disturbed sites, but less common in the 2 00 8 south. 6 SU 4 2 90 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 24 Atlas of Terrestrial Mollusca

Arion hortensis aggregate - Garden Slug

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 8 The three species of the Arion hortensis 6 4 aggregate are only reliably separable by 2 30 8 dissection. The majority of records refer to 6 4 the species aggregate. All records are 2 20 included in the map (left). It occupies a wide 8 6 4 range of habitats, including urban areas 2 10 where it can be a pest. The VCH describes it 8 6 as “common and general”. SP 4 2 00 8 6 The few dissected specimens indicate the SU 4 2 presence of two species, A. hortensis sensu 90 8 6 stricto (form ‘R’) and A. distinctus (form 4 2 ‘A’) within in the county (see maps below). 80 8 Both seem to be equally widespread and are 6 4 probably common throughout the county. 2 Both remain seriously underrecorded. 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Arion hortensis Férussac 1819 (form ‘R’) Arion distinctus Mabille 1868 (form ‘A’),

2 2 50 post-1985 50 post-1985 8 8 6 pre-1985 6 pre-1985 4 4 2 2 40 40 8 8 6 6 4 4 2 2 30 30 8 8 6 6 4 4 2 2 20 20 8 8 6 6 4 4 2 2 10 10 8 8 6 6 SP 4 SP 4 2 2 00 00 8 8 6 6 SU 4 SU 4 2 2 90 90 8 8 6 6 4 4 2 2 80 80 8 8 6 6 4 4 2 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Nationally A. distinctus is believed to be common across much of the British Isles, whereas A. hortensis sensu stricto is much more confined to southern counties.

Oxfordshire Museums Service – Biological Records Centre 25 Atlas of Terrestrial Mollusca

Arion intermedius Normand 1852 - Hedgehog Slug

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 This common species is most 8 6 numerous in rough grassland, where it 4 2 typically occurs amongst moss and 30 8 grass litter or within tussocks. It is 6 4 found in a variety of sites from 2 20 churchyards and road verges to semi- 8 6 natural meadows, chalk grassland and 4 2 open woodland. It was not recorded 10 8 until 1907 (), but 6 SP 4 considered “numerous around Oxford” 2 00 in the VCH. 8 6 SU 4 2 90 Nationally, a very common slug in a 8 6 wide array of habitats. 4 2 80 8 6 4 2

2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 20 30 40 50 60 70 80

VITRINIDAE Vitrina pellucida (Müller 1774) - Pellucid Glass Snail

2 50 8 post-1985 vc.22 & vc.23 6 pre-1985 4 2 40 This is a common species throughout 8 6 the county but living specimens are 4 2 rarely encountered outside of the 30 8 winter months. It occurs under stones 6 4 and dead wood in variety of habitats 2 20 from churchyards to semi-natural 8 6 woodland. Recorded as “common and 4 2 10 general” in the VCH. 8 6 SP 4 2 It is very common throughout the 00 8 British Isles often in damp woodlands 6 SU 4 and grassland. 2 90 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 26 Atlas of Terrestrial Mollusca Vitrea crystallina (Müller 1774) - Crystal Snail

2 50 8 post-1985 vc.22 & vc.23 6 pre-1985 4 2 40 A widespread and common species 8 6 within the county. It is found amongst 4 2 moss and leaf litter, under stones and 30 8 dead wood or within tussocks in a wide 6 4 array of rural and urban sites. 2 20 Described as “common and general” in 8 6 the VCH, but this also includes records 4 2 for V. contracta. 10 8 SP 6 4 Throughout the British Isles this is 2 00 common in a variety of damp sheltered 8 6 SU 4 places. 2 90 8 6 4 2 80 8 6 4 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Vitrea contracta (Westerlund 1871) - Milky Crystal Snail

2 50 8 post-1985 vc.22 & vc.23 6 pre-1985 4 2 40 Another widespread ssail found in a 8 6 wide array of rural and urban sites. It 4 2 often occurs with V. crystallina, 30 8 especially in drier sites, such as chalk 6 4 grassland, but it generally seems to be 2 20 less frequent. The two species are not 8 6 distinguished in older records. 4 2 10 8 It is common throughout the British SP 6 4 Isles but preferring drier sites such as 2 00 8 calcareous grassland or screes. 6 SU 4 2 90 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 27 Atlas of Terrestrial Mollusca Nesovitrea hammonis (Ström 1765) - Rayed Glass Snail

2 50 8 post-1985 vc.22 & vc.23 6 pre-1985 4 2 40 Although common throughout the 8 6 county it is never found in large 4 2 numbers. It is more prevalent in 30 8 damper sites such as woodland, 6 4 wetlands and meadows, occasionally in 2 20 shady churchyards. It can be found 8 6 under dead wood, amongst moss or 4 2 within tussocks. In the VCH it is 10 8 widely recorded. SP 6 4 2 00 8 It is common throughout the British 6 SU 4 Isles in marshes, damp grassland and 2 90 woodland. 8 6 4 2 80 8 6 4 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Aegopinella pura (Alder 1830) - Clear Glass Snail

2 50 8 post-1985 vc.22 & vc.23 6 pre-1985 4 2 40 This species is common throughout the 8 6 county, especially in well wooded 4 2 areas. It can be found under stones and 30 8 dead wood or amongst leaf litter in a 6 4 wide range of, mainly rural, habitats. 2 20 In the VCH it is noted as occurring 8 6 “sparingly”. 4 2 10 8 A common snail throughout the British SP 6 4 Isles, typically in deciduous woodland. 2 00 8 6 SU 4 2 90 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 28 Atlas of Terrestrial Mollusca

Aegopinella nitidula (Draparnaud 1805) - Smooth Glass Snail

2 50 8 post-1985 vc.22 & vc.23 6 pre-1985 4 2 40 A very common species. Although 8 6 most often encountered amongst moss 4 2 in woodlands or scrub it occurs in most 30 8 habitats. It can be numerous at some 6 4 sites and dead shells often abound. 2 20 Given as “common and general” in the 8 6 VCH. 4 2 10 8 In woodlands, rough grass and SP 6 4 disturbed sites throughout the British 2 00 Isles it is very common. 8 6 SU 4 2 90 8 6 4 2 80 8 6 4 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxychilus draparnaudi (Beck 1837) - Draparnaud’s Glass Snail

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 Unusually for a snail, this species is 8 6 carnivorous, feeding mainly on 4 2 earthworms. A fairly recent colonist 30 8 into the county, it was first recorded at 6 4 the Oxford Botanic Gardens in 1926 2 20 and had become well established in 8 6 Oxford gardens by 1935 (VCH). It has 4 2 since increased substantially and is 10 8 now widespread throughout the 6 SP 4 county. Typically it occurs under large 2 00 stones or among debris in churchyards, 8 6 SU gardens and scrubby waste ground, 4 2 90 seldom far from houses. 8 6 4 2 This ancient introduction is widely 80 8 established and increasing across much 6 4 of England, typically in gardens. 2 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 20 30 40 50 60 70 80

Oxfordshire Museums Service – Biological Records Centre 29 Atlas of Terrestrial Mollusca

Oxychilus cellarius (Müller 1774) - Cellar Snail

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 A common species occurring in a wide 8 6 range of habitats, including disturbed 4 2 sites, under stones and dead wood or 30 8 amongst moss and leaf litter. Listed as 6 4 “common and general” in the VCH. 2 20 8 6 Nationally a very common snail 4 2 occurring throughout the British Isles. 10 8 6 SP 4 2 00 8 6 SU 4 2 90 8 6 4 2 80 8 6 4 2

2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 20 30 40 50 60 70 80

Oxychilus alliarius (Miller 1822) - Garlic Snail

2 50 8 post-1985 vc.22 & vc.23 6 pre-1985 4 2 40 This common species is widespread, 8 6 but has a preference for more acidic 4 2 sites, such as woodlands on the 30 8 Chiltern clay cap or the Midvale sands, 6 4 even in conifer plantations. It is found 2 20 under stones and dead wood and when 8 6 handled it emits a pungent smell of 4 2 garlic. The VCH considered it to be 10 8 “generally distributed but local”. SP 6 4 2 00 8 Another very common species in 6 SU 4 Britain. 2 90 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 30 Atlas of Terrestrial Mollusca

Oxychilus helveticus (Blum 1881) - Swiss Glass Snail

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 Although widespread and common 8 6 across much of the county it is scarce 4 2 in the Clay Vales and on the Lias clays 30 8 in the north. It predominantly inhabits 6 4 woodlands, usually under dead wood, 2 20 but also in shady churchyards and 8 6 damp places generally. It can emit a 4 2 slight smell of garlic when provoked, 10 8 but never as potent as O. alliarius. It is 6 SP 4 widely recorded in the VCH. 2 00 8 6 SU Possibly an old introduction, but now 4 2 locally common throughout England 90 8 and Wales. 6 4 2 80 8 6 4 2

2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 20 30 40 50 60 70 80

Zonitoides excavatus (Alder 1830) - Hollowed Glass Snail

2 50 8 post-1985 vc.22 and vc.23 6 pre-1985 4 2 40 The only likely records held at the 8 6 OBRC for this species, typical of wet 4 2 acidic woodland, are from Bagley 30 8 Wood (1922) and from a Chiltern 6 4 beech wood (1984). It has not been 2 20 refound at either site. The habitat at the 8 6 Chiltern site seems unsuitable and may 4 2 be erroneous. There is no reason to 10 8 doubt the Bagley record, but its status 6 SP 4 in the county is uncertain. 2 00 8 6 SU 4 Outside Oxfordshire this species is 2 90 locally common in wet acidic 8 6 woodland, especially in western 4 2 Britain. 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 31 Atlas of Terrestrial Mollusca

Zonitoides nitidus (Müller 1774) - Shiny Glass Snail

2 50 8 post-1985 vc.22 & vc.23 6 pre-1985 4 2 40 This widespread species is associated 8 6 with wet habitats, such as marshes, and 4 2 is common on much of the Thames 30 8 flood plain. It can be found under dead 6 4 wood, amongst moss and flood debris 2 20 or within tussocks. Described as “well 8 6 distributed and common” in the VCH. 4 2 The large proportion of old records 10 8 may indicate a decline in some parts of SP 6 4 the county. 2 00 8 6 SU 4 It is common throughout most of 2 90 England and Wales and tolerant of 8 6 flooding. 4 2 80 8 6 4 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

MILACIDAE - Keeled Slugs Milax gagates (Draparnaud 1801) - Jet Slug

2 50 8 post-1985 vc.22 & vc.23 6 pre-1985 4 2 40 This is a rare slug in Oxfordshire and 8 6 may be an ancient introduction. There 4 2 are just two recent records, from under 30 8 stones in a churchyard and in a large 6 4 domestic garden. First recorded in 2 20 1891, there are several records listed in 8 6 the VCH. However, it is possible that 4 2 some may refer to T. budapestensis, as 10 8 then unrecognised from Britain. SP 6 4 2 00 8 Although locally common in the south- 6 SU 4 west, it is uncommon inland and 2 90 typically found in gardens. 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 32 Atlas of Terrestrial Mollusca

Tandonia sowerbyi (Férussac 1823) - Keeled Slug

2 50 8 vc.22 & vc.23 6 4 2 40 Typically for an introduced species this 8 6 large slug inhabits disturbed sites, such 4 2 as gardens and churchyards, and can be 30 8 common in some urban areas. It is 6 4 most easily found by turning large 2 20 stones. The VCH describes it as 8 6 “apparently increasing” but this may 4 2 include records for T. budapestensis, as 10 8 then unrecognised in the county. 6 SP 4 2 00 Throughout Britain this species is a 8 6 SU frequent inhabitant of gardens. 4 2 90 8 6 4 2 80 8 6 4 2

2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 20 30 40 50 60 70 80

Tandonia budapestensis (Hazay 1881) - Budapest Slug

2 50 8 vc.22 & vc.23 6 4 2 40 Although not recorded in the VCH, 8 6 this modern introduction may have 4 th 2 reached Oxfordshire early in the 20 30 8 century and may have been long 6 4 confused with T. sowerbyi or M. 2 20 gagates. Its presence in the county was 8 6 not confirmed until 1988 and it is has 4 2 proved to be the commonest of the 10 8 Milacid slugs by far. Found under 6 SP 4 stones and general debris, typically in 2 00 gardens and churchyards, but also in 8 6 SU hedgerows, disturbed woodland and 4 2 90 scrub. 8 6 4 2 Accidentally introduced into Britain 80 8 around the turn of the century, it is 6 4 now common and increasing in many 2 areas. 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 20 30 40 50 60 70 80

Oxfordshire Museums Service – Biological Records Centre 33 Atlas of Terrestrial Mollusca

Boettgerilla pallens Simroth 1912 - Worm Slug

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 First recorded in Britain in 1972, this 8 6 introduced slug was first collected at 4 2 Oxford in 1988. It is now well 30 8 established in gardens, churchyards 6 4 and scrubby waste ground throughout 2 20 Oxfordshire. Its subterranean habits 8 6 make it rather elusive and it is most 4 2 easily found by turning very large 10 8 stones, especially in the winter months. 6 SP 4 2 00 Known from a handful of sites during 8 6 SU the 1970’s this species is now locally 4 2 90 frequent in many parts of Britain and 8 6 continues to increase. 4 2 80 8 6 4 2

2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 20 30 40 50 60 70 80

LIMACIDAE - Keelback Slugs Limax maximus Linné 1758 - Leopard or Great Grey Slug

2 vc.22 & vc.23 50 post-1985 8 6 pre-1985 4 When fully grown this can be a large 2 40 and attractively marked species. 8 6 Although characteristic of woodland (it 4 2 is particularly common in the well- 30 8 wooded Chiltern Hills), it also inhabits 6 4 waste places and gardens and will even 2 20 enter houses. Usually found under dead 8 6 wood, but in wet weather it will readily 4 2 climbs tree trunks. Given as “common 10 8 and general” in the VCH. SP 6 4 2 00 8 It is common throughout the British 6 SU 4 Isles. 2 90 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 34 Atlas of Terrestrial Mollusca

Limax cinereoniger Wolf 1803 - Ash-black Slug

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 This, Britain’s largest slug, is 8 6 surprisingly adept at concealing itself 4 2 within large pieces of dead wood. In 30 8 the autumn it is much easier to find, 6 4 often close to fungi. It is a 2 20 characteristic inhabitant of ancient 8 6 deciduous woodlands in the Chiltern 4 2 Hills, often on acidic soils. Outlying 10 8 populations near Oxford (known since SP 6 4 the 1850’s) and in the west of the 2 00 county (a recent discovery) suggest it 8 6 SU 4 may be awaiting discovery in other 2 90 suitable (acidic) woodlands. 8 6 4 2 Beyond Oxfordshire this ancient 80 8 woodland species is widespread, but 6 4 local and declining. 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Limax flavus Linné 1758 - Yellow Slug

2 vc.22 & vc.23 50 post-1985 8 6 pre-1985 4 Although widely recorded this species 2 40 is not encountered with any frequency. 8 6 Typically found in churchyards or 4 2 gardens, it can be found under large 30 8 stones or within crevices on stone 6 4 walls. Described as “common and 2 20 general” in the VCH, it seems to have 8 6 become less common in recent years. 4 2 10 This may reflect the loss of its 8 6 preferred habitat: cellars, kitchens and SP 4 2 sculleries. 00 8 6 SU 4 Throughout much of Britain this 2 90 remains a frequent species. 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 35 Atlas of Terrestrial Mollusca

Malacolimax tenellus (Müller 1774) - Slender Slug

2 50 post-1985 8 vc.23 only Notable b. UKBAP (c) 6 pre-1985 4 2 40 All records for this elusive slug are 8 6 from ancient Beech woodland in the 4 2 Chiltern Hills, often associated with L. 30 8 cinereoniger. Mature specimens, found 6 4 in autumn, are bright yellow and are 2 20 characteristically found on the 8 6 underside of fungi, nearby beneath 4 2 dead wood or climbing adjacent Beech 10 8 trunks. There is no evidence of a local SP 6 4 decline and it may even be under- 2 00 recorded. The VCH gives one site, 8 6 SU 4 Checkendon, where it still occurs. 2 90 8 6 This is an uncommon and declining 4 2 species associated with ancient 80 8 woodlands, including Caledonian pine- 6 4 forest. 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Lehmannia marginata (Müller 1774) - Tree Slug

2 vc.22 & vc.23 50 post-1985 8 6 pre-1985 4 In well-wooded areas, such as the 2 40 Chiltern Hills, this species can be 8 6 locally common. Although strongly 4 2 associated with deciduous woodlands, 30 8 it also occurs in churchyards and 6 4 gardens. Often found under stones and 2 20 dead wood, but in damp weather, large 8 6 numbers will readily climb tree trunks 4 2 or walls, becoming very conspicuous. 10 8 Listed as “general and common” in the SP 6 4 VCH. 2 00 8 6 SU 4 It is common throughout much of 2 90 Britain especially in the west. 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 36 Atlas of Terrestrial Mollusca

Lehmannia valentiana (Férussac 1821) - Greenhouse Slug

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 This recent addition to the county list 8 6 was first recorded from Oxford in 4 2 1993. It is presently known from three 30 8 garden centres, where it is most likely 6 4 introduced from plant nurseries. It is 2 20 probably present at other sites, 8 6 including gardens, where it may be 4 2 confused with L. marginatus. 10 8 SP 6 4 This species has long been known from 2 00 glasshouses in Britain but is becoming 8 6 SU 4 more frequently recorded outside in 2 90 gardens and garden centres. 8 6 4 2 80 8 6 4 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Deroceras laeve (Müller 1774) - Marsh Slug

2 vc.22 & vc.23 50 post-1985 8 6 pre-1985 4 This small slug is characteristic of 2 40 marshy ground, such as beside rivers, 8 6 in fens and wet glades in woodlands. It 4 2 is usually fairly elusive, but can be 30 8 found in small numbers amongst moss, 6 4 under dead wood or within tussocks. In 2 20 the VCH it is described as “scarce but 8 6 in most districts”. 4 2 10 8 Throughout the British Isles this is a SP 6 4 very common wetland slug. 2 00 8 6 SU 4 2 90 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 37 Atlas of Terrestrial Mollusca

Deroceras reticulatum (Müller 1774) - Grey Field Slug

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 This ubiquitous species is the most 8 6 commonly encountered slug in the 4 2 county and may be found anywhere. It 30 8 can be particularly numerous at 6 4 disturbed sites and can be a severe pest 2 20 in gardens and arable fields. It should 8 6 occur in all tetrads. The VCH simply 4 2 says “ubiquitous”. 10 8 SP 6 4 It is equally abundant and ubiquitous 2 00 throughout the British Isles. 8 6 SU 4 2 90 8 6 4 2 80 8 6 4 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Deroceras panormitanum (Lessona & Pollonera 1882) (=D. caruanae) - Caruana’s Slug

2 50 post-1985 8 6 pre-1985 4 vc.22 & vc.23 2 40 8 6 First recorded at Oxford in 1984, this 4 2 modern introduction was not known to 30 8 the VCH. Today it is a fairly common 6 4 slug throughout the county and 2 20 possibly continues to increase. It is 8 6 typically found under stones and 4 2 amongst debris in disturbed sites, such 10 8 as gardens, churchyards and waste- SP 6 4 ground. 2 00 8 6 SU 4 Not known in Britain until 1931 this 2 90 species is now widely established 8 6 particularly in western areas. 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 38 Atlas of Terrestrial Mollusca Euconulus fulvus (Müller 1774) - Tawny Glass Snail

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 This has proved to be a fairly common 8 6 snail, especially in the drier well 4 2 wooded Chiltern Hills. It occurs in a 30 8 wide variety of habitats, including 6 4 woodlands, grassland and churchyards, 2 20 usually amongst moss and leaf litter, 8 6 within tussocks or under dead wood. It 4 2 is described as “sparingly but generally 10 8 distributed” in the VCH, but this also SP 6 4 includes records for E. alderi. Indeed 2 00 the two species were not differentiated 8 6 SU 4 within the county until the 1980’s and 2 90 some of the pre-1985 records may refer 8 6 to E. alderi. 4 2 80 8 Throughout the British Isles this is a 6 4 common snail. 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 870 2 4 6 880

Euconulus alderi (Gray 1840)

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 This species is less common than E. 8 6 fulvus, and prefers damper habitats, 4 2 such as flood meadows, fens or wet 30 8 woodlands. Searching amongst moss, 6 4 leaf litter or within tussocks can be 2 20 productive. It is apparently absent from 8 6 the waterless Chiltern Hills and 4 2 Berkshire Downs. None the less, the 10 8 two species often occur together and SP 6 4 were not distinguished in older records. 2 00 8 6 SU 4 It is also widespread throughout 2 90 Britain, but is more local than E. 8 6 fulvus. 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 39 Atlas of Terrestrial Mollusca FERUSSACIIDAE Cecilioides acicula (Müller 1774) - Blind Snail

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 This small blind species is exclusively 8 6 subterranean. It is often discovered by 4 2 turning large stones in gardens, 30 8 churchyards or grasslands on friable 6 4 lime-rich soils. It is widespread, but 2 20 elusive, and is certainly underrecorded. 8 6 For example, dead shells in mole hills 4 2 or flood debris are much more widely 10 8 encountered than living specimens. It SP 6 4 is widely recorded in the VCH. 2 00 8 6 SU 4 In the chalk and limestone areas of 2 90 south-eastern England this is a 8 6 common species but it becomes much 4 2 scarcer to the north. 80 8 6 4 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

CLAUSILIIDAE: Door Snails Cochlodina laminata (Montagu 1803) - Plaited Door Snail

2 vc.22 & vc.23 50 post-1985 8 6 pre-1985 4 This large species was considered very 2 40 scarce in the past and had a disjunct 8 6 distribution. The VCH notes it as “not 4 2 common, except (Chiltern) Beech 30 8 woods”. It genuinely seems to have 6 4 become more widespread in the last 2 20 century and is now locally common 8 6 wherever woodlands occur on 4 2 calcareous soils. It is easily found 10 8 under dead wood, often with C. SP 6 4 bidentata, and will readily climb tree 2 00 8 trunks in wet weather. 6 SU 4 2 90 A locally common species in 8 6 woodlands on calcareous soils 4 2 throughout England and Wales. 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 40 Atlas of Terrestrial Mollusca

Macrogastra rolphii (Turton 1826) - Rolph’s Door Snail

2 50 post-1985 8 vc.22 & vc.23 Notable b. 6 pre-1985 4 2 40 First recorded at South Hinksey, near 8 6 Oxford, in 1880 this species was 4 2 considered extinct by the VCH. Some 30 8 70 years later (1951) it was 6 4 rediscovered at the nearby Wytham 2 20 Woods. Recent surveys have shown it 8 6 to occur in several nearby ancient 4 2 calcareous deciduous woodlands. 10 8 Outlying colonies occur in the 6 SP 4 Evenlode Valley and on the Chiltern 2 00 escarpment. It lives amongst moss and 8 6 SU leaf-litter, occasionally beneath dead 4 2 90 wood, but unlike C. laminata and C. 8 6 bidentata it never climbs trees. 4 2 80 8 This uncommon species is confined 6 4 mainly to the south-east of England. 2 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 2 4 6 8 20 30 40 50 60 70 80

Clausilia bidentata (Ström 1765) - Common Door Snail

2 vc.22 & vc.23 50 post-1985 8 6 pre-1985 4 Within Oxfordshire, this ubiquitous 2 40 snail is one of the most frequently 8 6 encountered species. In woodlands and 4 2 hedgerows it can be extremely 30 8 numerous, especially under dead wood, 6 4 and during wet weather it readily 2 20 climbs trees in large numbers. Given as 8 6 “common and general” in the VCH. 4 2 10 8 This species is abundant over much of SP 6 4 England and Wales. 2 00 8 6 SU 4 2 90 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 41 Atlas of Terrestrial Mollusca

Balea perversa (Linné 1758) - Tree Snail

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 A widespread but rarely encountered 8 6 snail. It is usually found within 4 2 crevices or amongst moss on tree 30 8 trunks or old stone walls, but becomes 6 4 elusive in dry weather. Old willow 2 20 pollards or senescent elders are often 8 6 favoured. Recent records from mossy 4 2 'Cotswold slate' roofs suggest it may be 10 8 more widespread than previously SP 6 4 thought. It is widely recorded in the 2 00 VCH. 8 6 SU 4 2 90 This predominantly western species 8 6 has declined in many areas as a result 4 2 of air pollution, but is making a 80 8 comeback in many areas. This may 6 4 also be the case in Oxfordshire. 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 870 2 4 6 880

TESTACELLIDAE: Shelled Slugs Férussac 1819 - Maugé’s Slug

2 vc 22 only 50 post-1985 8 6 pre-1985 4 This carnivorous slug is not listed in 2 40 Collinge (1891) or the VCH, but there 8 6 is an old record from in 4 2 1905 held by the OBRC. There have 30 8 been no subsequent records. It is a 6 4 particularly elusive species and may 2 20 have been overlooked, but it has not 8 6 been seen in central England for 4 2 several decades. 10 8 6 SP 4 Believed to be an introduction, this 2 00 8 apparently rare slug was widely 6 SU 4 recorded across southern England in 2 90 the early twentieth century, but all 8 6 modern records are from south-western 4 2 areas. 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 42 Atlas of Terrestrial Mollusca

Testacella haliotidea Draparnaud 1801 -

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 This elusive predator is 8 6 most easily found in autumn by turning 4 2 large stones or hand sorting soil in 30 8 churchyards or mature gardens. 6 4 Although probably underrecorded it 2 20 does seem to be genuinely scarce. 8 6 Described as “not at all uncommon” in 4 2 Collinge (1891) and widely recorded in 10 8 the VCH it seems to be much less SP 6 4 common now, perhaps reflecting the 2 00 decline in manured vegetable plots and 8 6 SU 4 increased use of garden chemicals. 2 90 8 6 Records for this is apparently rare slug 4 2 are widely scattered throughout 80 8 England. 6 4 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 870 2 4 6 880

Testacella scutulum Sowerby 1821 - Shield Slug

2 vc.22 & vc.23 50 post-1985 8 6 pre-1985 4 There are old records for this species. 2 40 Collinge (1891) cites a record from 8 6 Oxford in 1887, but adds; “I am now 4 2 inclined to think that these specimens 30 8 were T. haliotidea”. There have been 6 4 no reliable modern records for the 2 20 county. Recently a few possible 8 6 specimens have been examined, but the 4 2 10 characters used to separate the two 8 6 species seem unreliable and the SP 4 2 identification of T. scutulum is 00 8 tentative. 6 SU 4 2 90 The few recent records for this slug are 8 6 widely scattered across England. 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 43 Atlas of Terrestrial Mollusca Candidula intersecta (Poiret 1801) - Wrinkled Snail

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 A widespread snail typical of dry 8 6 grassland on lime rich soils and can be 4 2 numerous on poorly vegetated areas in 30 8 quarries. In dry weather it can prove 6 4 very elusive, but tends to miraculously 2 20 re-appear following rain. It was 8 6 considered much scarcer in the past 4 2 and is described as “very local” in the 10 8 VCH. SP 6 4 2 00 A common species on the English 8 6 SU 4 chalk and limestone, but becomes more 2 90 scarce elsewhere. 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Candidula gigaxii (Pfeiffer 1850)

2 50 8 post-1985 vc.22 & vc.23 6 pre-1985 4 2 40 This species is usually associated with 8 6 C. intersecta but is perhaps more 4 2 tolerant of rougher calcareous 30 8 grasslands. The VCH considered this 6 4 to be the commoner of the two species, 2 20 but there are relatively few recent 8 6 records. This may indicate a decline in 4 2 the county or possible confusion 10 8 between the two. SP 6 4 2 00 8 This species is locally frequent in 6 SU 4 southern England especially on lime- 2 90 rich soils. 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 44 Atlas of Terrestrial Mollusca

Cernuella virgata (da Costa 1778) - Striped Snail

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 A common banded snail found 8 6 amongst dry grassland, often with 4 2 Candidula species. Typical sites 30 8 include road verges, churchyards and 6 4 semi-natural grassland, usually on lime 2 20 rich soils. Considered “abundant and 8 6 general” in the VCH. 4 2 10 8 The distribution of this common SP 6 4 species follows outcrops of calcareous 2 00 rock across England and most coastal 8 6 areas. SU 4 2 90 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Helicella itala (Linné 1758) - Heath Snail

2 50  post-1985

8 vc.22 & vc.23 6  1970-1985 4 pre-1970 2 sub-fossil 40 This large and distinctive snail was

8 6  widely recorded in the VCH and in 4 2 subsequent years. In recent decades it 30

8 has declined dramatically at many

6 

4 sites, especially in the Cotswolds, and 

2 

20  there are relatively few recent records

8

   

6  for live specimens (most easily found

4

   

2  in the autumn). It is confined to species 10  8 rich calcareous grassland (never 6 SP 4 heathland!) and the Chilterns and 2

00  Berkshire Downs remain a stronghold. 8

6 Several colonies occur on prehistoric

SU 4

2 

90 earthworks and railway cuttings, often



8  maintained by rabbit grazing.  6 

4   2 

80 8  Nationally, inland populations of this 6 4 species are declining, but coastal 2 populations seem to be thriving. 202468 30 2468 40 2468 50 2468 60 2468 70 2468 80

Oxfordshire Museums Service – Biological Records Centre 45 Atlas of Terrestrial Mollusca

Monacha cantiana (Montagu 1803) - Kentish Snail

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 This is a possible nineteenth century 8 6 colonist of the county. Certainly, in 4 2 1857 it was only known from 30 8 Headington, Oxford. It steadily spread 6 4 to become “abundant and general” 2 20 across the county by 1938 (VCH). 8 6 Today it is one of our commonest 4 2 snails and can occur in large numbers 10 8 in gardens and other disturbed sites. It SP 6 4 also inhabits road verges and open 2 00 grasslands, but seldom penetrates far 8 6 SU 4 into woodland. 2 90 8 6 This ancient introduction is very 4 2 common in much of southern England 80 8 and continues to spread north-west. 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Ashfordia granulata (Alder 1830) - Silky Snail

2 50 post-1985 8 vc.22 & vc.23 UKBAP (c) 6 pre-1985 4 2 40 A widespread but local species within 8 6 the county. It inhabits wet sites, such 4 2 as marshes and rough riverside 30 8 meadows. It can be found amongst 6 4 moss and dead vegetation, beneath 2 20 dead wood or within tussocks. First 8 6 recorded at Bullingdon Bog, Oxford, in 4 2 10 1857 and considered “rare” in the 8 6 VCH. SP 4 2 00 8 This species has a patchy distribution 6 SU 4 throughout Britain and can be locally 2 90 frequent, but is virtually absent from 8 6 mainland Europe. 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 46 Atlas of Terrestrial Mollusca

Perforatella subrufescens (Miller 1822) - Brown Snail

2 50 post-1985 8 vc.22 only 6 pre-1985 4 2 40 The only confirmed Oxfordshire record 8 6 for this snail is by Dr K.N.A.Alexander 4 2 from an ancient deciduous woodland 30 8 near Faringdon in 1995. It is quite 6 4 likely to occur in other acidic 2 20 woodlands in the west of the county. It 8 6 is listed in the VCH as “very rare”, but 4 2 these and other more recent records are 10 8 believed to be unreliable and have not SP 6 4 been mapped. 2 00 8 6 SU 4 In northern and western areas of 2 90 Britain this is a frequent species of 8 6 ancient deciduous woodlands, but 4 2 declining or absent elsewhere. 80 8 6 4 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Perforatella rubiginosa (Schmidt 1853)

2 50 post-1985 8 vc.23 only RDB2 6 pre-1985 4 2 40 At its only known Oxfordshire locality 8 6 it is found within sedge tussocks and 4 2 amongst flood debris on a Thames-side 30 8 marsh. Here it occurs with two 6 4 superficially similar species, Ashfordia 2 20 granulata and Trichia hispida, which 8 6 does not help detection. For this reason 4 2 it may be overlooked elsewhere 10 8 (confusion with Trichia plebeia is also SP 6 4 likely), but other apparently suitable 2 00 8 sites have been searched without 6 SU 4 success. 2 90 8 6 This very rare species was only 4 2 discovered in Britain in 1981 and is 80 8 known from a handful of periodically 6 4 flooded sites in the lower Thames 2 Valley. 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 47 Atlas of Terrestrial Mollusca

Hygromia cinctella (Draparnaud 1801) - Girdled Snail

2 50 post-1985 8 vc.23 only 6 pre-1985 4 2 40 This Mediterranean snail is the most 8 6 recent colonist of the county. In May 4 2 2000 a single specimen was collected 30 8 under stones in the grounds of a school 6 4 at Oxford. The species may be present 2 20 at other sites and, judging by national 8 6 trends, may quickly spread to new 4 2 areas. 10 8 SP 6 4 It has been known from south Devon 2 00 since the 1950’s, but in recent years 8 6 SU 4 has colonised several counties in 2 90 southern England, including Berkshire 8 6 and Gloucestershire. 4 2 80 8 6 4 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Trichia striolata (Pfeiffer 1828) - Strawberry Snail

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 Within Oxfordshire this is second most 8 6 widely recorded species. It is 4 2 ubiquitous in all habitats and is readily 30 8 found under stones, dead wood and 6 4 amongst general debris. In disturbed 2 20 sites, such as churchyards, it can occur 8 6 in large numbers. It should occur in all 4 2 10 tetrads. Given as “abundant and 8 6 general” in the VCH. SP 4 2 00 8 It is common throughout most of the 6 SU 4 British Isles. 2 90 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 48 Atlas of Terrestrial Mollusca

Trichia plebeia (Draparnaud 1805)

Although widely recorded from the county in past, the reliability of these records has recently been questioned. Known Oxfordshire specimens have been re-examined, but all have proved erroneous. The VCH notes that it “occurs with T. hispida” and many records, seem to be based on misidentification of that species. At one site specimens have proved to be Perforatella rubiginosa.

In the English T. plebeia is locally common and there are confirmed records in Northamptonshire, just north of the county, where it occupies moist and sheltered places. It is possible that the species may also occur in the north of Oxfordshire. In the absence of reliable records the species has not been mapped.

Trichia hispida (Linné 1758) - Hairy Snail

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 This common snail is most frequently 8 6 encountered in damp habitats, such as 4 2 meadows, woodlands and even 30 8 churchyards, but also on dry calcareous 6 4 grasslands. Typically it is found under 2 20 stones and dead wood but also within 8 6 tussocks. In the VCH it is described as 4 2 “common and general”. 10 8 SP 6 4 A common species throughout most of 2 00 8 the British Isles. 6 SU 4 2 90 8 6 4 2 80 8 6 4 2 202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 49 Atlas of Terrestrial Mollusca

Arianta arbustorum (Linné 1758) - Copse Snail

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 A fairly common species in many parts 8 6 of the county. It frequents rough 4 2 herbage in a variety of damp habitats, 30 8 including gardens, but predominantly 6 4 in woodlands and marsh. It is 2 20 considered “general but in restricted 8 6 colonies” by the VCH. 4 2 10 8 This widespread species can be locally SP 6 4 common in many areas of Britain. 2 00 8 6 SU 4 2 90 8 6 4 2 80 8 6 4 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 870 2 4 6 880

Helicigona lapicida (Linné 1758) - Lapidary Snail

2 50  post-1985 8 vc.23 only 6 1970-1985 4 pre-1970 2 sub-fossil 40 The VCH described this large and 8 6 attractive snail as “common on the 4 2 Chilterns” where it mainly inhabited 30 8 Beech woodland. Outlying colonies 6 4 occurred on limestone grasslands and 2

20 quarries of the Cotswolds and the

8 6  Midvale Ridge. By the 1980’s it had

4 2  disappeared from all its old haunts, 10 8 although sub-fossil shells could still be 6 SP 4 found. Two new sites were discovered 2 00 in the 1990’s with live specimens on 8 6 churchyard walls in the west and SU 4 2 beside a sunken track in a Chiltern 90 8

6 wood. Its future existence in the county

4  is uncertain.  2 

80 8  6 4 This local species is declining in many 2 parts of England. 202468 30 2468 40 2468 50 2468 60 2468 70 2468 80

Oxfordshire Museums Service – Biological Records Centre 50 Atlas of Terrestrial Mollusca

Cepaea nemoralis (Linné 1758) - Brown Lipped Snail

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 This is one of the commonest species 8 6 within the county, frequenting rough 4 2 herbage in a variety of habitats from 30 8 gardens and churchyards to grassland 6 4 and open woodland. It is regarded as 2 20 “common and general” in the VCH. 8 6 4 2 It is equally common throughout much 10 8 of Britain. SP 6 4 2 00 8 6 SU 4 2 90 8 6 4 2 80 8 6 4 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 870 2 4 6 880

Cepaea hortensis (Müller 1774) White Lipped Snail

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 This species is often found with C. 8 6 nemoralis but is somewhat more local. 4 2 It has a rather patchy distribution and 30 8 seems to become much more scarce in 6 4 the north of the county. Although 2 20 found in a variety of habitats, including 8 6 gardens, it has a strong preference for 4 2 damp woodlands and marsh. In the 10 8 VCH it is considered “common and SP 6 4 general” 2 00 8 6 SU 4 It is common throughout much of the 2 90 British Isles. 8 6 4 2 80 8 6 4 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Oxfordshire Museums Service – Biological Records Centre 51 Atlas of Terrestrial Mollusca

Helix aspersa Müller 1774 - Garden Snail

2 50 post-1985 8 vc.22 & vc.23 6 pre-1985 4 2 40 Throughout the county this is a 8 6 familiar species in gardens, and other 4 2 disturbed sites, where it can occur in 30 8 large numbers. It can also be found in 6 4 most rural habitats, including a few 2 20 woods, but is much less abundant. 8 6 Simply described as “ubiquitous” in 4 2 the VCH. 10 8 SP 6 4 An ancient introduction, this species is 2 00 very common in much of southern 8 6 SU 4 England. 2 90 8 6 4 2 80 8 6 4 2

202 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 8702 4 6 880

Helix pomatia Linné 1758 Roman or Edible Snail

2 50 8 post-1985 vc.22 & vc.23 Notable b UKBAP (c) 6 pre-1985 4 casual 2 40 This, Britain’s largest snail, is very 8 6 local in the county. It occurs on friable 4 2 30 lime-rich soils, most notably on the 8 6 Cotswold oolite, but also along the 4 2 Chiltern escarpment. It favours open 20 8 scrubby banks, such as railway cuttings 6 4 and woodland edges. Temporary 2 10 introductions may occur elsewhere, but 8 6 these rarely persist for long. First SP 4 2 00 recorded at Stonesfield in 1853 and 8 6 reported in the VCH to occur “in some SU 4 2 numbers locally” within this area. 90 8 6 4 This ancient introduction has a patchy 2 80 distribution on lime-rich soils in 8 6 southern England, but is becoming 4 2 increasingly rare across Europe and is 20 2 4 6 8302 4 6 8402 4 6 8502 4 6 8602 4 6 870 2 4 6 880 legally protected.

Oxfordshire Museums Service – Biological Records Centre 52 Atlas of Terrestrial Mollusca