Excerpts from Jim Conrad's
from the May 10, 2009 Newsletter, issued from the Siskiyou Mountains west of Grants Pass, Oregon:
BANDED FOREST SNAIL
Accompanying the cold that brought the lizards inside was a lot of rain inducing more than the usual large number of Banded Forest Snails, MONADENIA FIDELIS, to appear. You can see one of those crossing my fingers above.
The snail in that picture was so cold and lethargic that it didn't pull in its head when I picked it up, so I got to photograph features that usually remain overlooked. For example, look at the breathing hole below:
At the hole's right you may notice a certain irregularity. That's the anus.
Above the snail is looking at us. The word "looking" is OK to use because snails more or less see -- at least see enough to recognize movement and shades of gray. Of the four tentacles projecting toward us, which are the eyes? You can barely make out dark "eye spots" at the tip of the top, longer tentacles, so the top tentacles se can be considered eye stalks. However, vision is more like an afterthought for the snail. The tentacles are most sensitive to touch. After that the bulbous structures at the tentacles' tips are primarily odor- sensing chemoreceptors.
By the way, aquatic snail species only bear one pair of tentacles while land snails like ours clearly have two.
Thanks to Karen in Mississippi, who has a book profiling the common snails and slugs, for IDing this snail for me.