Pusula identification

[paul monfils]

That's a tough one.  I have specimens of each species, plus a few I cannot assign to either species with certainty.  P. radians is supposed to have "a couple more ribs on the average than P. solandri" - not much help there when dealing with a single specimen.  P. radians tends to be more "flattened" than P. solandri.  In other words, the width to height ratio is greater in P. radians.  P. radians is described as having dark spots on the dorsum, but some P. solandri have such spots too.  How large is your specimen?  P. solandri seldom exceeds 15 mm, while P. radians often exceeds 20 mm.