Could you guys take a look at this plant. It is really small and was sold as a terrarium plant. What is it?
Unknown Aroid Possibly an Philodendron
Your picture does not "show and tell" much about your plant Warren. Until someone else chimes in here, take a look at this Philodendron and see if there are any similarities to the plant you have. Hopefully, someone will give you a definite I.D.
http://www.exoticrainforest.com/Philodendron%20pusillum%20pc.html
The plant is just too juvenile to be able to make a determination. Can you separate a single plant and photograph it closeup in detail?
The best link for you to read would appear to be the one on ontogeny and variation. Assuming this is a Philodendron it is going to change dramatically as it begins to grow and mature. Good photos of both sides of the leaf blade, the petiole that supports the leaf and the stem (central axis) of the plant may offer some clues but it is likely you'll need to grow this one for awhile.
http://www.exoticrainforest.com/Natural%20variation%20within%20aroid%20and%20%20plant%20species.html
Steve
PS: Rachel, thanks for giving the link to my site but I can't be certain this is a Philodendron at this size.
I just blew your photo up 300% and can't see any veins in the leaves. Is there any type of vein formation on either side of the leaf blade other than the midrib? This may not be an aroid.
Steve