30 December 2010

Little snails on the rocks

In the park near our house there is a ledge covered with large limestone rocks situated not too far above a lake. This artificial structure probably has some sort of drainage function into the lake below. However, it is not clear where the water may be coming from. Anyway, what concerns here us is not the hydrology of the park, but the little snails that call the rocks their home. I took these pictures of them yesterday.

The snails were, of course, dormant. As you can see in the picture below, there were both big ones and little ones.

I believe these are a Vallonia species, probably Vallonia costata. However, even the largest snails I saw did not have the typical thickened and reflected lip characteristic of the adults of the genus.

A closer search on a warmer day should turn up more specimens to pinpoint the identity of the snails.

1 comment:

Anonymous said...

Looks like Vallonia costata to me, but we'll wait till you find what appears to be an adult individual. (I have to say I am not familiar with the possible US species that it could be.) But I did also want to say that in the UK, generally V. costata is happy in rather dry places, as long as it has limestone. V. pulchella on the other hand, which has a smooth shiny shell, likes damp places.

Susan J. Hewitt