Victorian Non-Marine Molluscs -3 



by Brian J. Smith 



Ihcic are four or five species of 

 introduced snails of the family Hcli- 

 ddae which look very much alike 

 jjUJ which are of leu ponfused Thev- 

 ars all sandhill snails and, where 

 thc> occur, usually reach near plague 

 piuporiions. 



Tlwhu pisona (Mullcr) 



Pus is a medium si/.cd globular 

 shell ahout 15 to 20 mm in diameter 

 usually bearing numerous dark brown 

 vpir.il bands on a white background. 

 The inside of the aperture is often 

 pink but the most obvious character 

 H. separate this species from the 

 other similar species is nearly closed 

 umbilicus or hole in the centre of 

 Ihe spiral under the shell. In all the 

 species described below the umbilicus 

 is open and obvious lo a greater or 

 Is'ssei estent. This snail is found very 

 commonly on coastal sand-dunes 

 alone the entire Victorian coast-line 

 where it can occur in very great 

 numbers. However recently thi* 

 species has also been recorded along 

 the Murray, so may occur in other 

 dry sandy areas. 



Genus //e/t't <■//</ 



species of this genus have white 

 shells with concentric brown bands 

 of s. living thickness These arc 

 glohular lo flattened discoid in shape 

 and all have a prominent wide um- 

 bilicus. They live in saiuh flirty 

 dry situations along the coastal fringe 

 and inland, associated with places 

 frequented by man. HflheHo Wr- 

 ffllto and hhluclla rifjcn.t are loo 

 very closely similar species inhabit- 

 ing mainlv the drier areas in cen- 

 tral Western Victoria. They can be 

 veen clinging |P clusters to the fence- 

 roles in mam of the drier areas of 



February, 1971 



this part of Ihe State. These seem 

 largely confined to inland areas. The\ 

 can be separated with diflicully 

 chiefly by their spire shape, thai ol 

 //. itexlcciti being much Hatter 



A small species of this genus. Heli- 

 ccllii rupenuu is found living with 

 Theba pisana m coastal dunes, and is 

 often confused with the iiiveniles ol 

 the latter species. However, it can be 

 readily separated by the presence ol 

 a large umbilicus. There may be 

 other Hciicella species introduced 

 into Ihe Stale but only, more collect- 

 ing can elucidate this. 



l-it:urc«. Aperlurc I a I and Ventral tbi 



U 7/ie'n/ piuma I note lack of 



umbilicus). 

 2 H. lii-rlla Vttg»m 



//e/i. <7/u mtrm (small M/et 

 ir»,.wlng< hy M.« Ht.ylti* PUn< ) 



45 



