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 look-alike could naturally be affixed to the glass, as long as it is done in such a way that it is not confused with the CE marking". Selling beer in unmeasured glasses without using some other form of calibrated measure is illegal. Half-pint, one-third pint and two-thirds pint (schooners) glasses are also available, and are subject to the same laws. Although the glass must be accurately-calibrated, industry guidelines only require a pint to be at least 95% liquid, allowing 5% of the pint to consist of the foamy 'head'. The Campaign for Real Ale (CAMRA) has described this practice as