what's almost like a cinnamon fern?

 I bought three semi-dormant cinnamon ferns on eBay a while ago, and
now that they're well-unfolded one of them seems to be something else.
It looks almost like a cinnamon fern except the individual leaflets
(if that's the correct term) are smoother and some of the fronds have
spore-forming bodies on them.  I've heard the ostrich fern compared to
the cinnamon fern, but from the pictures I've seen of the ostrich fern
the leaflets don't look smooth enough to be what I've got.  What other
possibilities are there?  Could this just be a freak cinnamon fern?

 
Osmunda cinnamomea, cinnamon fern, has separate fertile and sterile fronds.
The two don't look at all alike.  What I think you're describing is
sori (clusters of sporangia) dotted on the underside of the frond?

At any rate, cinnamon fern should look like this:
http://www.ct-botanical-society.org/ferns/osmundacinn.html

Is that even close to what you have?  Can you post a photo to a web page
and give us the URL?

 

I know what cinnamon ferns look like, I already had one and wanted
more.  I'll try to post a picture of the oddball later, it's rainy
today.

 Pictures are now at http://www.pbase.com/jim_shaffer/unknown_fern
(click the thumbnails, full-resolution images are still available)

 

Osmunda regalis?