It could be an Echinopsis as well. I'd wait to see what the blooms look like (come on, Spring!). tick tick tick tick...
Ray

You may be right about that dawn, but it looks like Echinopsis calochlora. E. calochlora maintains a beautiful glossy, grassy green coloured epidermis like that and has nicely rounded ribs also. Unfortunately, digging around in my archives failed to produce a pic for you, and the pics I've located through google are not clear either. Flowers are like E. multiplex only white.

CP

Ray & CP, You both could very well be right on the Echinopsis suggestion. For some stupid reason I keep leaning twards the notocactus side. At what temps should I keep this plant at for dormancy? I want to make sure it flowers for me for positive IDing. CP, the plants epidermis is actually more lighter green than the pic shows.

Thanks guys,
Dawn

Dawn, my E. calochlorum used to get cold dry winters (sometimes sub-zero centigrade), this seemed to suit it ok, it is probably as hardy as most of the Echinopsis species. I found it to be a shy flowerer, they can be quite (as Jeffrey H. so eloquently puts it) puppiferous, sometimes putting out pups at the expense of flowers.

CP

CP, Thanks for the info. I was planning on keeping it in a room where the temps will be at around 55f or in the other room that get as low as 40F. It should be safe than.

Dawn