snorkel... air vent... what the hell do i know? lol, yes, i am referring to the snorkel, johnny.
the hole in the tank is exactly as rick g. described. it's for the attachment of the shroud, and the snorkel cover in the pic seems to attach right into it and cover the snorkel's opening. hence, knocking out two birds out with one stone.
is it still possible to find this?