Double checking taxonomy of cerithium

[dave r]

I went through a whole shell collection made in the 1860's and mostly labeled 'South Sea Islands'!
You have to take note of the author and year when looking at latin names, sometimes a shell will have the same name by two different authors, then one is usually synonymised. This is what seems to have happened here. The one from the Caribbean being the synonym. It is actually quite straightforward.