Making a key in the normal fashion involves so many keys as to be
unusable in the normal manner of keys to a few species that are quite
handy.

Doing the key to all genera as a data base is about the only practical
system if one insists on having such a key.  Years ago, I made up such a
data base for about 50 genera found in Hawaii. The user filled in a set
of questions and answers about a large number of characteristics
entering choice 1 to 10.

To start with someone had to go through the questions and fill in the
answers for each genus/species to establish the data base.  This
essentially was a decimal digit for each question, about 25 digits long,
 making a simple list of 25 digit numbers for each genus/species.

Users would enter answers to all questions matching a shell in front of
them compiling a 25 digit number for the species. The program then
matched the user's answers with the data base number for each species,
coming up with a score for each data base species based on how
correct/incorect each digit was.  The final output was a list of
possibles in priority order.

Due to variability of shells, and the definite possibility of juveniles
being involved, present or absent protoconchs, etc. there is no perfect
answer.

A more nearly workable system is to have a computer scan the shell and
answer most of the questions in a relatively short time. But it wouldn't
handle radulae characteristics, and would also have to scan an
operculum.  Some years ago in the Hawaii State Science Fair, one student
had this type of computer scanner input that measured length, width,
location of periphery, and a few other things.  It worked to a
fair degree. Each species had a list of acceptable range of each
measurement and measurement ratio relying on a human to enter the
species name.  (She won a prize from HMS)

To get a perfect system, there would have to be a great number of
questions added such as numbr of whorls; animal characteristics; radula
type;  operculum size, shape, material, and location of nucleus; and in
the future DNA choices.  Collectors of dead shells would not have all
the answers available and would come up with more possibles.

If the DNA of an unknown species were available to a user, a computer
that had all DNA factors entered for each species could probably pick
out the species and subspecies.  Why not go all the way?  Just some work
in getting DNA for every species and someone who knew which species name
applied to each DNA set.  No problem.
--
                     Aloha from Wesley M. Thorsson
Editor of Internet Hawaiian Shell News, a monthly Internet Publication
           122 Waialeale St, Honolulu, HI  96825-2020,  U.S.A
       http://www.hits.net/~hsn                 [log in to unmask]