orthoceratidæ

pl. [Mod. Latin ortho ceras, gen it. orthocerat (is); Lat. fem. pl. adj. suff. ide. Palæont.: A family of tetrabranchiate Cephalopod a. The shell is straight, curved, or discoidal, with a small body-chamber, a contracted aperture, and a complicated siphuncle. or-thō-çer-a-tite, subst . [Mod. Lat. orthoceras (gen it. orthoceratis); suff. -ite ( Palæont .) (q.v.). Any individual of the genus Orthoceras, or the family Orthoceratide. ( Owen : Anat . Invert ., p.331.) orth-o-clāşe, s. [Pref. ortho- , and Gr. klasis =a fracture.) Min.: A monoclinic species of the felspar group of uni silicates of Dana. Hardne , 6-6.5; specific gravity, 2-44-2-62; luster, vitreous when pure, cleav age-planes of altered kinds sometimes pearly; color, white, gray, reddish; transparent to translucent; fracture, conchoidal when obtained. Composition: Silica, 64-6; alumina, 185; potash, 16:9=100; soda sometimes replaces a part of the potash. Dana distinguishes the following varieties: 1. Ordinary, (1) Adularia, including moonstone and valencia nite; (2) Sunstone, or aventurine felspar; (3) Necronite; (4) Amazon-stone, now referred to Microcline (q. v.); (5) Erythrite; (6) Sanidine, or gla y felspar; (7) Chester lite, now referred to Microcline (q. v.); (8) Microcline of Breithaupt; (9) Loxoclase; (10) Paradoxite; (11) Cottaite; (12) Muldan; (13) Lazurfelspar; (14) Perthite; (15) Murchisonite. 2. Compact Orthoclase or Orthoclase-Felsite, including ma ive kinds constituting rocks; it is an e ential constituent of many rocks, granites, gnei es, syenites, . IMG:content-0382.png:[blocks in formation] diagonal (q. v.).) or-tho-di-ag-o-nal, s . [Pref. ortho- , and Eng. Crystal log.: The inclined lateral axis in the monoclinic system. It is at right angles to the verticle axis. ( Dana : Min . (ed. 5th), p. xxvi.) or-tho-dox, *or-tho-doxe, a . [Fr. orthodoxe, from Low Lat. orthodox us ; Gr. orthodoros of the right opinion, from orthos =upright, right, true, and dor a opinion; Sp. ortodoxo .] 1. Holding the right or true faith; sound in opinion or doctrine; espec. in religious opinions or doctrines; opposed to heterodox and heretical . chin, bench; go, gem; thin, this; IMG:content-0383.png:[blocks in formation] "Down with the orthodoxal train, All loyal subjects slay." Brome: The Saints ' Encouragement. (1643.) tor-tho-dox-al-1-ty, s . [Eng. orthodoxal ; -ity.] The quality or state of being orthodox; orthodoxy, orthodox ne . (Cudworth: Intell . System , p. 599.) for-tho-dox-al-ly, adv. [Eng. orthodoxal; -ly.] In an orthodox manner; in accordance with orthodoxy. *or-tho-dox-as-tic al, a . [Gr. orthos = right, true, and dozastikos -forming an opinion; dor a = an opinion.] Orthodox. "More orthodox as tical Christians than they them. selves."-Foxe: Martyrs, p. 258.