Viviparids will be much larger than hydrobiids in maximum size.  The
specimen has enough whorls to be reasonably mature.  I see that size
information is listed as not available, but hopefully they at least
know whether that photo was taken at high magnification or not.

I don't offhand know of any tall-spired viviparids in southern Mexico.
 It could also be a land snail that fell into the cenote.

On Wed, Mar 14, 2012 at 11:25 AM, Fabio Moretzsohn <[log in to unmask]> wrote:
> Thanks, Art
>
> You may be right about both. I was thinking the Mexican snail might be a
> hydrobiid, but looking at some photos of viviparids, it seems more likely to
> belong in that family.
>
> At first I thought the Texan shell was a thiarid, and even thought about
> Melanoides tuberculata, but after I looked at it under the microscope, the
> sculpture threw me off. Now looking at online photos of the species, I see
> that it has a wide range of conchological variation.
>
> I will pass your suggestions to my friends.
>
> Best,
> Fabio M.
>
>
> On Tue, Mar 13, 2012 at 9:06 PM, [log in to unmask]
> <[log in to unmask]> wrote:
>>
>> Not sure but the Mexican shell looks like a viviparid the other is
>> Melanoides tuberculata
>>
>> Connected by DROID on Verizon Wireless
>>
>>
>> -----Original message-----
>>
>> From: Fabio Moretzsohn <[log in to unmask]>
>> To: [log in to unmask]
>> Sent: Wed, Mar 14, 2012 01:19:09 GMT+00:00
>> Subject: [CONCH-L] Mystery snails
>>
>> A couple of friends asked me to ID the shells pictured in the album linked
>> below.
>>
>> All I know about the first one is that it was collected in a cenote (well
>> or sinkhole, usually with fresh or brackish water) in Yucatán, México. No
>> other details provided.
>>
>> The other shell was dredged from near Sabine Pass, Texas (depth not
>> provided). The shell length is about 10 mm. Sorry the color has not been
>> corrected; under natural light the shell looks more like the last photo.
>>
>> Photos can be see here:
>>
>> https://picasaweb.google.com/103218668018991980077/MysterySnails?authuser=0&authkey=Gv1sRgCOGKhNnt_9TBBA&feat=directlink
>>
>> You can send comments to me, the list, or post commenst on the album.
>>
>> Thanks,
>> Fabio
>>
>



--
Dr. David Campbell
Collections Assistant
The Paleontological Research Institution
1259 Trumansburg Road
Ithaca NY 14850

----------------------------------------------------------------------
[log in to unmask] - a forum for informal discussions on molluscs
To leave this list, click on the following web link:
http://listserv.uga.edu/cgi-bin/wa?SUBED1=conch-l&A=1
Type your email address and name in the appropriate box and
click leave the list.
----------------------------------------------------------------------