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In ancient astronomy, one of the concentric and eccentric revolving spherical transparent shells in which the stars, sun, planets, and moon were supposed to be set, and by which they were carried, in such a manner as to produce their apparent motions.

her, like the tube of a small telescope or a spyglass; especially (Mach.), constructed of concentric tubes, either stationary, as in the telescopic boiler, or movable, as in the telescopic chimney of a war vessel, which may be put out of sight by being lowered endwise.

An apothecium in certain lichens, having a spherical surface marked with spiral or concentric ridges and furrows.

ogens). -- Seeds with two or more cotyledons. Stems with the pith, woody fiber, and bark concentrically arranged. Divided into two subclasses: Angiosperms, having the woody fiber interspersed with dotted or annular ducts, and the seed contained in a true ovary; Gymnosperms, having few or no ducts in the woody fiber, a…

A circular tread; a gait by which a horse going sideways round a center makes two concentric tracks.

characterized by the arrangements of color, inclusions, etc., of a crystal in parallel or concentric layers, which usually follow the outline of the crystal, and mark the changes that have taken place during its growth. -- Zonal symmetry. (Biol.) See the Note under Symmetry.

Having zones, or concentric bands; striped.