In a recent publication (A Revision of the Scaphopoda from Australian
Waters) we encountered numerous old co-types lodged in an Australian
museum for various species which had been named and lodged in this
museum. We treated these lots as syntype lots and from them selected a
lectotype the others in the same lot becoming paralectotypes.
Achatina blainiana Poey 1851, cotypes MCZ No xxxyyy & xxxyyy would
probably then be syntypes and if a lectotype has not been selected then
it remains for some worker to do so.
Kev