They are what bats hange from.
The word 'cask' has two different meanings: 1: the quantity a cask will hold; 2: a cylindrical container that holds liquids
A cask is a very small barrel in which wines of high value were stored. Sometimes such wines were too expensive or valuable to come in the larger size barrel so they were stored and sold in smaller...
The meaning of the title is that cask is wine barrel, and the amontillado is a sort of dry wine.
The term 'crevice' has two distinct meanings: 1: a long narrow depression in a surface; 2: a long narrow opening