What are these?

[b.branscombe]

New zoos, were on a really good deal at the store. Got about 5 colonies of this size, all similar colour. Pic is washed out due to crap camera, outer rings are much more green as opposed to brown. Thanks.

 

[b.branscombe]

After looking through the zoaid site, it looks like they may be reverse gorilla nipples? What do you think?
Link Removed

 

[edwing206]

Those are very nice!

 

[distallassazn]

gorrilea nipples? or reverse gorilla nipples...

 

[SoCalLifer]

I have a bunch of those.