I'm not sure - but I'll give it a shot.

"per" is a Latin prefix used in two ways: (1) to designate "through" (as
in the english words percutaneous, perspiration, perforate, etc.); and
(2) as an intensive, designating "very much" or "completely" (as in the
shell names Distorsio perdistorta, Sthenorytis pernobilis, Siratus
perelegans, etc.)

Words from the root "spect" (both Latin and English) usually refer to
seeing or viewing
Latin:
specto - to look at or view
spectabilis - visible or worth seeing
English:
spectacle
spectator
inspect
spectacles (eye glasses)

OK, now comes the guesswork part.  Based on the above, I suspect that
the word "perspective" literally means something like "see through
completely".  I can think of two possible meanings for such a phrase.
First, it could simply mean very widely open, allowing one to freely
view inside - like the umbilicus of a sundial shell - like
Architectonica perspectiva!  However - and here is my pet theory -
sundials, and some other dorso-ventrally flattened shells (Gaza superba;
some land snails) have another characteristic that this term could apply
to.  The protoconch is often eroded away, creating a small opening into
the umbilical area, so that when you look into the umbilicus you can see
out through the apex (or vice versa).  That would be a good explanation
for the description "see through completely".

That's my guess.  But I really don't know.


Regards,
Paul M.