well, I hate to say it, but it looks some what like a ventricosa to me...
do you have a nursery label any where? do you know who produced it? Gublers?
I think it is fun to try and identify mystery plants, but we all need to remember, it will always be a mystery, we can not for certain determine this plants heredity, and as such, it should only be traded as an 'unknown'. if it is, say, sanguinea, or a hybrid of thorelli, and you trade it to someone who is looking for ventricosa, to cross later and create a new complex hybrid, then you have pretty much given that person a costly detour..
Just my 2 cents of caution! [img]http://www.**********.com/iB_html/non-cgi/emoticons/wink.gif[/img] but I do think ventricosa or ventrata!