Hi, Again, Rick!

I have one question.  Myra Keen regards ambiguous as an
intermediate form betwenn the northern M. nigritis and the
souther M. radix (yes, I know the genera have been
changed).  She gives the range of radix as from Panama to
southern Ecuador, and the range of nigritis as confined to
the Gulf of California.  She then regards ambiguus as
possibly not a distinct species, but as a transitional
form between the two species, with a range of Southern
Mexico to Panama.

What is your take on this?

Cordially,
Linda