horse shoe crabs, --wonderful other worldly creatures that they are, also have lens(and eyes) from from hard clear parts of of their shell..

they have no openings in the top part of their shell for the lenses, they 'light sensing' cells of their very primitive eyes (they have compound eyes) just nestle up against the clearish/translucent parts of the upper shell.

(you're inland, right? i don't know how far south horse shoe crabs are found--even if you were on the coast. they are still common in sheltered areas here in NY area. LI sound, well the bays and wet lands on Long island and CT, RI, and MA still harbor a large population.)


my other obsession