According to The Living Cowries by Burgess, C. cribellum can be separated from
C. esontropia "by its smaller size, its more cylindrical flattened shape, and
by the lack of a lateral callus on the columellar side.  In the dorsal view,
there is a flaring of the right anterior labial callus that gives C. cribellum
a quite characteristic cylindrical shape.  This flare is lacking in C.
esontropia.  Furthermore, there is an almost total absence of brown spotting
on the base and sides of C. cribellum.  The general appearance and tooth
structure are so similar in the two species that C. cribellum may be a dwarf
form of C. esontropia."
So stated Dr. Burgess in 1970.
Regards,
Paul M.