Secondary

(sēkun-da-re.) [Same der iv.] (Zool.) See FEATHERS.-S. circles. (Ast.) Circles pa ing through the poles of some great circle; thus the meridians and hour circles are secondaries to the equinoctial. There are also secondaries pa ing through the poles of the ecliptic, by means of which all stars are referred to the ecliptic.- S. colors. See COLOR.- S. rocks. (Geol.) The series of formations which intervene between the primary rocks and the tertiary, including the Tria ic or upper new red sandstone group(which rests upon the Permian or magnesian limestone group, the uppermost portion of the primary division), the Lias sic, Oolitic, and Cretaceous groups. There is so marked a difference between the fo ils of this series and those of the earlier and later series, as to induce geologists to believe that an indefinite series of ages elapsed between them. [s. 810]