This link may be helpful:
http://kaston.transy.edu/widow.html
To me, it resembles the right hand example of the northern widow, only with the two halves connected. I have seen a northern widow with a connected hourglass ( In Michigan, where as far as I know there is ONLY the northern widow). I'd do some more research however. Try browsing this forum, or using the search function here. There is a post not too far down the page called something like "Oklahoma widow ID"--it may be a helpful thread. Basically, I'd just search around here, and other sites and look at examples of both species. Search black widow in the yahoo photo gallery.