Species Vallonia excentrica Sterki, 1893
Vallonia excentrica, apical view. Diameter of shell: 2.2 mm.
© Copyright Dr John Stanisic BAAM Pty Ltd Queensland
Vallonia excentrica, ventral view.
Museums
Regional Maps
Species Vallonia excentrica Sterki, 1893
Eccentric Grass Snail
Compiler and date details
July 2012 - Dr John Stanisic
- Vallonia excentrica Sterki, V. 1893. Observations on Vallonia. Proceedings of the Academy of Natural Sciences, Philadelphia 45: 234-279 [252].
- Helix alexandrae Cox, J.C. 1864. Catalogue of Australian Land Shells. Sydney : John Alex Engel 44 pp. [this name pre-dates that of Sterki (1893) but has had limited usage].
Type data:
Status unknown, (presumed lost), Petersham and near Sydney, NSW.
Taxonomic Decision for Synonymy
Miscellaneous Literature Names
- Vallonia costata Müller, 1774. —
Smith, B.J. 1992. Non-Marine Mollusca. In, Houston, W.W.K. (ed.). Zoological Catalogue of Australia. Non-marine Mollusca. Canberra : Australian Government Publishing Service Vol. 8 xii 408 pp. [315] (lists this species as occurring in Australia, but Stanisic (pers. comm.) reports that some records of Vallonia costata still remain unconfirmed but that these are probably also referable to V. excentrica) - Vallonia pulchella (Müller, 1774). —
Smith, B.J. 1992. Non-Marine Mollusca. In, Houston, W.W.K. (ed.). Zoological Catalogue of Australia. Non-marine Mollusca. Canberra : Australian Government Publishing Service Vol. 8 xii 408 pp. [315] (lists Vallonia pulchella as occurring in Australia)
Stanisic, J., Shea, M., Potter, D. & Griffiths, O. 2010. Australian Land Snails. A field guide to eastern Australian species. Mauritius : Bioculture Press Vol. 1 595 pp. [110] (states that animals were misidentified as Vallonia pulchella from as far back as the mid-1800s when it was named Helix alexandrae)
Introduction
An introduced species common in gardens. Australian specimens of this species were until recently misidentified as Vallonia pulchella (Müller, 1774) a similar looking Holarctic species which differs in having the whorl coiling evenly centered inside the umbilicus. V. excentrica has regularly been implicated in damage to both ornamental and vegetable crop plants. Helix alexandrae Cox, 1864 described from the Sydney area, NSW appears to be an earlier name but has not been used since its inception. Various records of Vallonia costata ((Müller, 1774) from southeastern Australia remain unconfirmed and are probably referable to this species.
Distribution
States
New South Wales, South Australia, Tasmania, Victoria
Extra Distribution Information
Introduced into southern half of Australia as well as Norfolk and Lord Howe islands
Introduced from Europe.
IBRA
NSW, SA, Tas, Vic: Murray Darling Depression (MDD), Sydney Basin (SB), South East Coastal Plain (SCP), South East Corner (SEC), South Eastern Highlands (SEH), Tasmanian South East (TSE)
Other Regions
Lord Howe Island terrestrial & freshwater, Norfolk Island terrestrial & freshwater
Distribution References
Ecological Descriptors
Gardens.
Extra Ecological Information
In grass, under pots, rocks and drifts of leaves
Diagnosis
Shell very small, translucent white, smooth and silky, discoidal with flared body whorl; lip circular, greatly thickened and reflected; umbilicus wide with off-centre coiling; diameter to 2.2mm.
General References
Smith, B.J. 1992. Non-Marine Mollusca. In, Houston, W.W.K. (ed.). Zoological Catalogue of Australia. Non-marine Mollusca. Canberra : Australian Government Publishing Service Vol. 8 xii 408 pp. [315] (as Vallonia costata and Vallonia pulchella)
Common Name References
Stanisic, J., Shea, M., Potter, D. & Griffiths, O. 2010. Australian Land Snails. A field guide to eastern Australian species. Mauritius : Bioculture Press Vol. 1 595 pp. [110] (Eccentric Grass Snail)
History of changes
| Published | As part of group | Action Date | Action Type | Compiler(s) |
|---|---|---|---|---|
| 24-Jul-2012 | 24-Jul-2012 | MODIFIED | ||
| 26-Mar-2012 | ADDED |