exocyathoid expansion (ex-o-cy'-a-thoid). Growth of an additional intervallum in an archaeocyathid cup, which appears to have had an adherent function (TIP, 1972, pt. E, p.7).

peg-leg multiple . A multiple reflection involving successive reflection at different interfaces so that its travel path is not symmetrical. Sometimes refers to short-path multiples within thin beds, which result in transferring energy from the front of a wavetrain and adding it back later, and sometimes to long-path multiples, which lead to separate events.

fels . A rarely used term applied to massive metamorphic rock lacking schistosity or foliation, e.g., calcsilicate fels (Winkler, 1967). Cf: granofels.