look at the picss above
![Big Grin](images/smilies/biggrin.gif)
j/k mbbuna is your man for that
its usually easy to tell by looking at the mantle pattern and coloration. squamosas and maximas generally have scutes in the side of their shells, while croceas are smooth because they bore into rock. the best way to id is to look at the bysall opening, and thats where mbbuna comes in