Sextarius

Sextarius a Roman dry and liquid measure, which may be considered one of the principal measures in the Roman system, and the connecting point between it and that of the Greeks, for it was equal to the ξέστης of the latter; and there can be little doubt that the ξέστης was not an original Greek measure, but that the word was introduced into the Greek system from the Roman, for the purpose of establishing a unit of agreement. [QUADRANTAL] It was one-sixth of the congius, and hence its name: in the Greek system it was one-sixth of the χοῦς. It was divided, in the same manner as the As, into parts named uncia, sextans, quadrans, triens, quincunx, semissis, &c. The uncia, or twelfth part of the sextarius, was the CYATHUS; its sextans was therefore two cyathi, its quadrans three, its triens four, its quincunx five, &c. (Wurm, de Pond. &c. p. 118; Hultsch, Metrologie, p. 112: cf. the Tables at the end of the volume.)

[P.S]