CŎCHLĔA (κοχλίας), which properly means a snail, was also used to signify other things of a spiral form. (1) A screw, used in working clothes-presses, and oil and wine presses.--(2) A spiral pump for raising water, invented by Archimedes, from whom it has ever since been called the Archimedean screw.--(3) A peculiar kind of door through which the wild beasts passed from their dens into the arena of the amphitheatre. COCHLĔAR. (κοχλιάριον), a kind of spoon, which appears to have terminated with a point at one end, and at the other was broad and hollow like our own spoons. The pointed end was used for drawing snails (_cochleae_) out of their shells, and eating them, whence it derived its name; and the broader part for eating eggs, &c. Cochlear was also the name given to a small measure like our spoonful. CŌDEX, identical with _caudex_, as _Claudius_ and _Clodius_, _claustrum_ and _clostrum_, _cauda_ and _coda_, originally signified the trunk or stem of a tree. The name codex was especially applied to wooden tablets bound together and lined with a coat of wax, for the purpose of writing upon them, and when, at a later age, parchment or paper, or other materials were substituted for wood, and put together in the shape of a book, the name of codex was still given to them. In the time of Cicero we find it also applied to the tablet on which a bill was written. At a still later period, during the time of the emperors, the word was used to express any collection of laws or constitutions of the emperors, whether made by private individuals or by public authority, as the _Codex Gregorianus_, _Codex Theodosianus_, and _Codex Justinianeus_. COEMPTĬO. [MATRIMONIUM.]