(ran out of space on my 8" screen again!)
        F/F+, F+/F++, F+ high......some shells just DON'T fit conveniently into
a grade which includes several factors.  Improvisation is sometimes
nessessary!
 
        So, there you have it.  When purchasing  "sight unseen", one must also
bear in mind that grades do not take aesthetics ("beauty"- a rather
sujective term at best!) into account- a GEM specimen can be ugly as
sin, have no pattern at all, or at least nothing  one would wish to
stare at for too long!  The only insurance one has against improperly,
incompletely or inappropriately-described items, is a dealer's return
policy and practice.  Fortunately for the collector, most dealers will
fully refund or give credit for  items returned a) in their origional
condition, and b) within a reasonable (sometimes explicidly stated,
sometimes not) time-frame.
 
        Good luck, and good hunting!!
                                                                                        -Ross Mayhew,
        Your  Schooner (graded-with-care(Most of the time!!) )Specimen Shell
Molluscan-commodities Purveyor.