Diagnosis
Challengeridae without large fenestrae near peristome of shell. With two or more oral teeth, margin smooth or with one or two isolated teeth.
Species treated:
Protocystis acornis Haecker
Protocystis balfouri (Murray)
Protocystis bicornuta Schröder
Protocystis bicuspis Schröder
Protocystis harstoni (Murray)
Protocystis heterocentrota Peters
Protocystis macleari (Murray)
Protocystis micropelecus Haecker
Protocystis murrayi (Haeckel)
Protocystis sloggetti (Murray)
Protocystis swirei (Murray)
Protocystis thomsoni (Murray)
Protocystis triangularis Peters
Protocystis tridens Haeckel
Protocystis varians Borgert