Earth about under the oceans to for the continents. The crust and the cold, rigid, top of the upper mantle are collectively known as the lithosphere, and it is of the lithosphere that the tectonic plates are composed. Beneath the lithosphere is the asthenosphere, a relatively low-viscosity layer on which the lithosphere rides. Important changes in crystal structure within the mantle occur at below the surface, spanning a transition zone that separates the upper and lower mantle. Beneath the mantle, an extremely low viscosity liquid outer core lies above a solid inner core. The Earth's inner core might rotate at a
Common name or coinages; such names generally are difficult for laymen to learn, remember, and pronounce and so, in such books as field guides, biologists commonly publish lists of coined common names. Many examples of such common names simply are attempts to translate the Latinised name into English or some other vernacular. Such translation may be confusing in itself, or confusingly inaccurate, for example, "gratiosus" does not mean "gracile" and "gracilis" does not mean "graceful". The practice of coining common names has long been discouraged; de Candolle's "Laws of Botanical Nomenclature", 1868, the non-binding recommendations that form the basis of the modern