sps ID please

[ScubaSteve]

Ok, this is a toughy. If there are definite polyps growing at the top of each of the bumps on the top surface and definite polyps growing at the tips of each of the bumps on the growth edge then I'd lean more towards a. efflo (acropora tend to grow from their polyps where as monti's tend to extend their edges or tips without growing from a definte corallite). Here's an acro with a similar growth for but you can see the corallites which the "bumps" grow from (link). There are a few acros that can start growing like what you have, A. solitaryensis is one of them.

If the growth edge is relatively polyp free and the top surface has polyps growing between the bumps (verruculli I think they're called?) then it's definitely a montipora of some sort, though god knows what kind. Could be m. undata, but I don't think it is. Could be a Ly Seng?

I think you might just have to narrow it to which family it's from first.

Do you have an info like where it's from, how long you've had it (how old is it), etc that could help us narrow it down?