Bulla vernicosa? from Philippines

Dear Marina,
I began a reply to your question and then realised I had already discussed this question in a reply some time ago to a message from Atsushi Ono [#1511 ].

I've had another look at our quite large collection of Bulla shells from the Indo-West Pacific and it certainly looks as though colour pattern is variable within populations and inflated 'typical' B. ampulla shells are inevitably large and mixed with smaller shells which are narrower at the apical end. A supposed charcter of B. vernicosa is a narrowing of the aperture of the shell - which we can't see in photos of the live animals.

What is a major problem is that Bulla vernicosa was never figured in Gould's original description, and no specimen was found in Gould's collections meaning that it is impossible to know just what Gould meant by the name. In the Willan's 1989 review, which I mention in Ono's message,  Willans essentially agrees by starting his remarks with:
"A future monograph on the genus may consider Bulla vernicosa Gould, 1859 to be insufficiently described since the original diagnosis is inadequate and there is no designated type.."

In my opinion there are two separate questions to ask about Bulla. Firstly we need to know how many species there are and whether they vary in shell shape and colour as they grow. Secondly we then need to try and sort out which of the many names that have been given to shells over the last 150 years can be fitted to 'biologcal' species. In the meantime I think it is less confusing to call them all Bulla ampulla. Certainly in  large adults, the shell has an inflated, wide, opening but I have found no small shells with a similar shape so I can only assume that smaller animals have a narrower 'B. vernicosa ' shape.

Hopefully Manuel Malaquias's research will make it clearer.
Best wishes,
Bill Rudman