Help me identify this shell from Sanibel Island

[novice]

I found this shell last week during a very low tide on a sand bar off the southern coast of Sanibel Island.  I found a Junonia the same day and wasn't sure what I had, so I took both shells into a shell shop for some help with idenification.  The proprietor looked through a couple of books and couldn't find it, so she thought it might be a land snail.  Any help?  Here's a couple of pictures:

<a href="http://www.badongo.com/pic/4833239" target="_blank"><!-- m --><a class="postlink" href="http://www.badongo.com/pic/4833239">http://www.badongo.com/pic/4833239</a><!-- m --></a>
<a href="http://www.badongo.com/pic/4833250" target="_blank"><!-- m --><a class="postlink" href="http://www.badongo.com/pic/4833250">http://www.badongo.com/pic/4833250</a><!-- m --></a>

[dave r]

Hi. Yes it is a land snail but I know nothing about them, I am sure someone else will tell you. Congratulations on finding a junonia, I know people who have searched for years and not found one.
Dave

[novice]

Thanks, Dave.  I am really enjoying this site.  From what little I have read, there seems to be some system for "grading" shells.  Is it better to have a specimen of size with some minor defect(s), or a smaller one that is perfect?  I have been collecting only about 4 years and just by chance ended up on Sanibel, where the shelling bug bit me badly.  I have collected some very nice varieties.  So, I'm just curious.  Most of my nicest ones (in my opinion) were collected after storms near Sanibel.

[dave r]

Yes, after storms is possibly the best way to collect beached shells, a lot of deeper water species get brought up which you would not normally see (your junonia for instance) I often go to the beach here in England after a good storm to see what has ben cast up and have had some good results.
There is a system for grading shells; G=Gem, F=Fine, G=Good, C=Commercial ( or some would say Crap!), most shell books or websites will have this, but it is open to interpretation. A 'Gem' quality cowry for example should be absolutely flawless but there are species of shells that are never found in perfect condition, so you have a set of shells that are never 'Gem'. Some people quote 'Gem for species' which means it is about as good as it gets. Some Murex shells have a few tiny breaks on the fronds which are almost invisible, you have to look carefully or even use a lens to see them. I personally would say this is Gem but purists would not. Some also put a plus or minus after the grade to mean that it is 'not quite' or 'slightly better than' but this can lead to nit-picking.
As to small,perfect specimens or big flawed ones, I think it is all a matter of personal choice. At the end of the day it is your collection and whatever pleases you is the best.
Dave

[novice]

Thanks to both Dave and Paul for your prompt response.

[dave r]

Euglandina rosea is sometimes called the 'wolf snail'. It has been introduced to other countries with disastrous results as it predates on the local endemic snails. It was introduced to Hawaii where it has wiped out a large proportion of the very local endemic Achatinellid snails as has done similarly on other Pacific Islands. Sad to say some of the introductions were done deliberately with the intention to eradicate other 'pest species' such as Achatina.
Dave

[paul monfils]

Your shell is Euglandina rosea (Ferussac, 1821), a common carnivorous species that feeds on other land snails.