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 standard rulings. Starting in 2006, the NSAI "pint" mark, a circle featuring two wavy lines, between which "PINT" is written, with a year mark (last two digits), and a three digit batch code either side; has begun to be phased out with a European standard "PINT"/CE logo stamp . Smaller Pint glasses have been used in pubs and nightclubs though. In Israel, although officially defined as 568ml, pubs use the term rather arbitrarily and the "pints" served constitute a wide range of volumes (360ml–440ml). In the past, the custom was to serve beer in 330ml or 500ml in the original