n. pl. cap•su•lae (-lē′)
  1. A membranous structure, usually dense collagenous connective tissue, that envelops an organ, joint, or other part.
  2. An anatomical structure resembling a capsule or envelope.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Examples from the Web for capsula

Historical Examples of capsula