Australian Biological Resources Study

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Family VALLONIIDAE Morse, 1864

Grass-snails


Compiler and date details

March 2012 - Dr John Stanisic

1992 - Brian J. Smith, Museum Victoria, Melbourne

Introduction

Valloniids range from North America across Europe and north Africa into northern Asia. One or two species of Vallonia have been introduced into countries outside their native range where climatic conditions are favourable. A single introduced species, Vallonia excentrica, occurs in urbanised areas of temperate southern Australia.

Valloniids are herbivores and the species can reach very large numbers in dense mats of grass and under ground cover plants. They can also reach considerable population densities in greenhouses and plant nurseries.

 

Diagnosis

Valloniids have very small (diameter less than 5 mm) discoidal to turbinate shells. The subfamily Valloniinae (to which the Australian introduction belongs) is characterised by discoidal shells with flattened to slightly raised spires, strongly impressed sutures, either smooth or radially ribbed sculpture, rounded whorls, a medium to wide umbilicus, circular aperture and thickened reflected lips. Shells are translucent to transparent and of a silky lustre and colour varies from white to corneous. The animal is pale in colour (cream) with relatively short club-like ocular tentacles.

 

History of changes

Note that this list may be incomplete for dates prior to September 2013.
Published As part of group Action Date Action Type Compiler(s)
24-Jul-2012 24-Jul-2012 MODIFIED
27-Jun-2012 27-Jun-2012 MODIFIED
12-Feb-2010 (import)