External gills usually contains muscle tissue, and may be moved by the animal as a free appendage, in order to stir up stagnant water. The stalk is lined by many thinly walled filaments (fimbriae), containing the majority of blood vessels used in gas exchange. Animals usually have one external gill originating on each gill arch (except the hyoid), which leads to there being three pairs of external gills in salamanders, and four in the gilled larvae of lungfish. External gills External gills are the gills of an animal, most typically an amphibian, that are exposed to the environment, rather than set inside
Pint glass is now rarely the case and lined glasses are found mostly at enthusiasts' events such as beer festivals, serious cask ale pubs, and breweries' own bars. Beer in Australia is formally measured in metric units, but draught beer is commonly ordered and sold in glasses approximating imperial measures, including a 570 ml pint. (In the state of South Australia, "pint" refers to a 425 ml (¾ pint) glass, known as a schooner in the rest of Australia.) As in the UK, certified glassware must be used; the capacity of the beer glass is defined by either the brim or, where