CIRCULUS

(Lat.), n. m. Su6rk(ki2rk)'u2l(u4l)-u3s(u4s). Dim. of circus, a ring. Gr., KvxAos. 1. In chemistry, an iron instrument formerly used for cutting circular portions of gla . It was applied hot, and then suddenly cooled. 2. In anatomy, an object or part of a circular form. 3. A name for several circular instruments used by the older surgeons. 4. In botany, a ring. [A, 325, 491 (o, 21 ); L, 94.] C. arteriosus Halleri. A vascular plexus upon the surface of the sclerotic at the point of entrance of the optic nerve, formed by branches of the short ciliary arteries. [L, 44.] C. arteriosus irid is (seu irid is major). Fr., cercle arteriel de Viris. Ger., gro er Gefd kreis der Regenbogenhaut. It., circolo arterioso delV iride. An arterial plexus which encircles the outer edge of the iris. [L, 31.] C. arteriosus irid is minor. Ger., kleiner Gefd kreis der Regenbogenhaut. It., circolo piccolo arterioso delV iride. A circular arterial plexus in the pupillary region of the iris. [L, 31, 142.] C. arteriosus musculi ciliaris [Leber]. A circular arrangement of the arterioles in the center of the ciliary muscle. O, no; 0, not; O, whole; Th, thin; Th, the; U, like oo in too; [s. 295]