BRERC Snail Key

7/31/2019 BRERC Snail Key

1/19

Key to theSNAILSof the

Bristol RegionAndrew DawTessa Ivison

This publication has been supported by The Bristol MagpiesA friends group of Bristols Museums, Galleries and Archives


2/19

Bristol Regional Environmental Records Centre (BRERC)

www.brerc.org.uk

BRERCThird FloorBristol Central LibraryCollege GreenBristolBS1 5TL

Tel: 0117 9349833

Fax: 0117 9273918

Email: [email protected]

Page 2 of 20
http://www.brerc.org.uk/http://www.brerc.org.uk/


3/19

SNAILSof the

Bristol RegionExternal Characteristics

Shapes of Shell

Pointed Globular Flat

Shell Features

Page 3 of 20


4/19

Shell Features

Counting Whorls Draw a line across the shelllined up with the centre.

The number of completewhorls (first whorl shown in

red) will match the number oftimes the line crosses thespiral here 3.

Add on the amount for anyincomplete whorls to give thefinal count This gives atotal of 3.25 whorls for thisexample.

WhorlsA = Slowly expanding (ortightly packed) whorls.

B = Rapidly expandingwhorls.

Teeth Some species of snails have

teeth like features in themouth of the shell.

IllustrationsEach set of illustrations for asnail will include a life-sizerepresentation of the snail inthe bottom left hand corner.

The other parts of theillustration will be shown at ascale indicated bya scale bar in cm or mmanda magnification (e.g. 3x).

Page 4 of 20


5/19

Key

1 Height of shell greater than width ...

2

Height of shell not greater than width ...

18

2 Mouth of shell to left (sinistral) ...

3

Mouth of shell to right (dextral) ...

5

Page 5 of 20


6/19

TALL, THIN, LEFT SIDED SHELLS

Tree SnailBalea (Balea) perversa3 Teeth absent ...

Mouth squareRocky outcrops & stone walls

Teeth present ...

4

4Plaited Door Snail

Cochlodina laminataRolphs Door SnailMacrogastra rolphii

Two-toothed Door SnailClausilia (Clausilia)

bidentata

Shell smooth, glossy &translucent with only faintgrowth lines.Common, climbs trees & wallswhen wet.

Distinct vertical ribbing, widestpoint of shell greater than 3mm.Woodland leaf litter & rockyoutcrops

Distinct growth lines, widestpoint of shell less than 3mmLeaf litter in woodland &hedges

TALL, THIN, RIGHT SIDED SHELLS

5 Height greater than 10 mm ...6

Height between 4 -10 mm ...9

Height up to 4 mm ...13

Page 6 of 20


7/19

TALL, THIN, RIGHT SIDED SHELLS GREATER THAN 10mm

6Mouth greater than half the height of thewhole shell.Very rapidly expanding whorls.

...8

Mouth less than half the height of thewhole shell.

7

7Round-Mouthed Snail

Pomatias elegansPointed Snail

Cochlicella (Cochlicella)acuta

Mountain BulinEna montana

Shell wide and thick with deephorizontal striations.Live specimens haveoperculum (trap door)Common in moist calcareousareas.

Very tall & thin, though heightvariable (10-30 mm)Shell white or ginger with orwithout dark bands or blotchesCoastal dunes & grassland.

Found in ancient woodland andhedgerowsRare

See 12 (Merdigera obscura)

Amber Snail

Succinea putris

8Shell greater than 12mm in height.

Adult snail has a pale body colour.

...

Common in fens, marshes andreed-beds

Pfeiffers Amber SnailOxyloma (Oxyloma)

elegans

Shell no more than 12mm in height.Adult has a dark body colour.

...

Similar habitats to S. Putris

Page 7 of 20


8/19


9/19

TALL, THIN RIGHT SIDED SHELLS LESS THAN 4 mm TALL

13 Mouth with one or no teeth ......... 14Mouth with more than one tooth ......... 17

14 Mouth with distinctly thickened lip ......... 15Mouth without thickened lip ......... 16

15

Chrysalis SnailLauria (Lauria) cylindracea

Moss SnailPupilla (Pupilla) muscorum

Single tooth contiguous with lipLip of the shell is pale in fresh specimens.Common, often found under ivy on stone walls

Single or no tooth, lip not connected.Pale stripe behind mouth of shell.Open grassland, rocky outcrops, walls & sanddunes.

16Point Snail

Acicula fuscaChrysalis SnailsColumella sp.

Shell with distinct vertical ribbingmoist leaf litter or moss in ancient woodland

Shell with only very faint striationsCommon in damp and calcareous areas

Page 9 of 20


10/19

TALL, THIN RIGHT SIDED SHELLS LESS THAN 4 mm TALL

17Herald Snails

Carychium tridentatum &C. minimum

English Chrysalis SnailLeiostyla anglica

Common Whorl SnailVertigo (Vertigo) pygmaea

Illustrated: Carychiumtridentatum

Examination of internal shellcharacteristics needed. See

Kerney & Cameron.Variety of habitats. C. minimumprefers wetter places.

Mouth pinchedDamp places in woods &

marshes

Full mouth!Dry calcareous grassland &

sand dunes

SHELL GLOBULAR OR FLAT IN SHAPE

18 Width of shell greater than 25mm ......... 19

Width of shell 7 25mm ......... 20

Width of shell 3 - 7mm ......... 34

Width of shell less than 3mm ......... 37

Page 10 of 20


11/19

WIDTH OF SHELL GREATER THAN 25 mm

Roman SnailHelix (Helix) pomatia19 Shell creamy yellow .........

Loose calcarious soil, generally not in gardens.

Common Garden SnailCornu aspersum

Shell blotched, stripedor flecked dark brown .........

Umbillicus absent. Found in gardens, generallynot in woodland or scrub.

WIDTH OF SHELL 7-25 mm

20 Shell sharply keeled ......... 21Shell with blunt or no keel ......... 22

Page 11 of 20


12/19


21Lapidary Snail

Helicigona lapicidaGirdled Snail

Hygromia (Hygromia) cinctella

Large umbilicusRocky ground & stone walls in calcareous areas

Small umbilicusWoods, hedgerows, orchards & gardens

note size difference and relative umbillicus size

see also 24 (Candidula) and 30 (Trochulus (Trochulus) striolatus)

22Shell with dark spiral bands, flecking or

blotching

......... 23

Shell white, yellow or brown with nodarker bands or blotching

......... 28 (Helicidae)

23 Shell with flecking or blotching with orwithout dark spiral band ......... 24

Shell with dark spiral bands but noflecking or blotching

.........

25

Page 12 of 20


13/19


24Copse Snail

Arianta arbustorumWrinkled Snail & Eccentric

SnailCandidula intersecta &

Candidula gigaxii

Rounded SnailDiscus (Gonyodiscus)

rotundatus

Illustration: Candidulaintersecta

Shell globular and may have

blotchesMay be confused with 19(Cornu aspersum), notepresence of umbilicus here.Moist habitats

The amount of stripes on the

shell can be variable, or absent.Height of shell less than ofwidth

Shell spire flattened withCandidula gigaxii.

Calcareous areas

Consider young specimens of26 (Cernuella virgata).

Shell flattened, very large

umbilicusMoist areas

25Base colour of shell whitish ......... 26

Base colour of shell yellow, brown orpinkish brown

......... 27

26Banded Snail

Cernuella (Cernuella) virgataHeath Snail

Helicella itala

Shell globular, spire raised (height at least ofwidth), and umbilicus small.The amount of stripes on the shell can bevariable, or absent.Dry, exposed calcareous areas.

Flattened on top, large umbilicusDry, exposed calcareous areas.

Page 13 of 20


14/19


White-lipped SnailCepaea (Cepaea) hortensis27 Shell with white lip .........

Brown-lipped SnailCepaea (Cepaea) nemoralisShell with brown lip .........

*young andgrowing snails may lack lip makingidentification difficult

The number and thickness of stripes are very variable with both C. hortensisand C. nemoralis.

The colouration of the shells can be variable too, from yellow, through brown to pink.

GLOBULAR SHELLS 7-25 mm WIDEWITH NO DARKER BANDS OR DARK BLOTCHING

28 Shell hairy ......... 29 Warning:Hairs may wear off adultsandJuveniles of severalspecies are hairy

Shell not hairy ......... 30

Page 14 of 20


15/19


29Hairy Snail

Trochulus (Trochulus) hispidusSilky Snail

Ashfordia granulata

Obvious umbilicusCommon in a variety of habitats.See also 30 (Trochulus (Trochulus) striolatus)

Very small umbilicusDamp, shady places.

Warning: hairs may wear off, check in the umbillicus. Juveniles of many species are hairy.

Strawberry SnailTrochulus (Trochulus)

striolatus30 Shell has dull keel with pale band justinside lip of shell.Adult shell usually greater than 10mmwide.

.........

Gardens, hedges, woodlands* hairy when young

Shell not like this ......... 31

Kentish SnailMonacha (Monacha)

cantiana31 Shell colour white to transparent, pinkishtinge near mouth .........

Not found in woodland

Page 15 of 20


16/19

Shell colour not white to transparent,pinkish tinge near mouth 32


32 Shell flattened, glossy or waxy,obviously wider than tall .........Aegopinella & Oxychilus

See Table 1.

Shell not this shape ......... 33

Table 1 Oxychilus and Aegopinella Characteristics

Adult Shell Width& No. of Whorls

Spire Shell colour

Draparnauds SnailOxychilus (Oxychilus)draparnaudi

11-16 mm5.5-6 whorls

very flattened yellow-brown, slightlyopaque, waxy

Cellar Snail

Oxychilus (Oxychilus)cellarius

9-12 mm

5.5-6 whorls

very flattened very pale, transparent,

glossy

Glossy Glass SnailOxychilus (Oxychilus)navarricus subsp.helveticus

8-10 mm5 whorls

slightly raised light brown, yellowishtinge, very glossy

Garlic SnailOxychilus (Oxychilus)alliarius

6-8 mm4-4.5 whorls

slightly raised yellowish brown togreenish, almosttransparent.

Smooth Glass SnailAegopinella nitidula

8-10 mm4.5 whorls

slightly raised yellow-brown, waxy

Clear Glass SnailAegopinella pura

3.5-4 mm3.5 whorls

slightly raised

Shiny Glass SnailZonitoides (Zonitoides)nitidus

5-6 mm4.5 whorls

raised, more thanAegopinella. Almosttriangular cross-section

pale brown, transparent,shiny

Hollowed Glass SnailZonitoides (Zonitellus)excavatus

6-7 mm4.5 whorls

raised, more thanAegopinella. Almosttriangular cross-section.

pale brown, translucent,glossy

Rayed Glass SnailNesovitrea (Perpolita)

hammonis

3.5-4 mm3.5 whorls

slightly raised, rise morerounded than

Aegopinella

pale brown, translucentwith distinct striations

Page 16 of 20


17/19

Dusky Snail

Zenobiella subrufescens33 Shell less than 10mm .........

Damp wooded areas

Shell more than 15 mm ......... 27 Cepaea sp.

GLOBULAR SHELLS 3 7 mm WIDEPellucid Glass Snail

Vitrina pellucida34Shell With rapidly expanding body whorl

Live animal

Pellucid GlassSnailVitrina pellucidaLive animal mostlyseen in winter,mantle pale

Or

Greater PellucidGlass SnailPhenacolimaxmajorLive animal mostlyseen in summer,mantle dark

Variety of moist habitats

Shell more tightly coiled ......... 35

a Tawny Glass Snail

Euconulus fulvus agg.

35Shell almost triangular .........

Various moist habitats

Shell flattened ......... 36


18/19


19/19

BRERC Snail Key

Documents

Transcript of BRERC Snail Key