Also (in sense 2) conca. [L. concha, It. conca: see prec.]
† 1. Zool. A shell; a bivalve mollusk; = CONCH 1, 2. Obs.
1755. T. Amory, Mem. (1769), II. 216. A display of all the most beautiful conchæ, various marcasites, corals, and fossil gems.
1776. Da Costa, Elem. Conchol., 94. Eight principal classes or families, viz. … 4. Limpets. 5. Conchæ, or Bivalves.
2. Archit. = CONCH 5; also, a coved ceiling.
1613–39. I. Jones, in Leoni, Palladio’s Archit. (1742), I. 39. The manner of Arches are … Rotonda, a Lunette, and a Conca.
1832. Gell, Pompeiana, I. vi. 103. The walls of the alcoves were blue and the concas or coves red.
1853. Ruskin, Stones Ven., II. iii. § 14. The apse is roofed by a concha or semi-dome.
1875. Parker, Gloss. Archit., Concha, name applied to the apse from the shell-like shape of the vault.
3. An ancient Roman vessel shaped like a shell; CONCH 4.
16[?]. Evelyn, Mem. (1857), I. 109. The admirable figure of Marforius, casting water into a most ample concha.
4. Anat. and Zool. a. The central concavity of the external ear, which communicates with the auditory meatus; sometimes used for the whole external ear.
1683. Phil. Trans., XIII. 259. That part of the Ear which we call the Concha from its resemblance to the entrance of a snail-shell.
1706. Phillips (ed. Kersey), Concha … in Anatomy, the winding of the Cavity or Hollow of the Inner part of the Ear.
1842. E. Wilson, Anat. Vade Mec., 461. The large central space to which all the channels converge is the concha.
1866. Huxley, Phys., viii. (1869), 233. The outer extremity of the external meatus is surrounded by the concha or external ear…. The concha can be moved in various directions by muscles.
b. Another term for the vulva. [So in L.]
1847. Ramsbotham, Obstetr. Med., 54. This has obtained the name of concha or fossa navicularis, and it contains within its precincts the clitoris [etc.].
c. Any one of the three turbinated bones of the nose (c. inferior, media, superior).
d. A depression enclosed by a circle of feathers, surrounding the eye in some birds.
1834. R. Mudie, Brit. Birds (1841), I. 100. [The eyes of the harrier] are provided with a concha, or circle of feathers, radiating from the orbit.
1874. Wood, Nat. Hist. (1881), 278. The funnel-shaped depression round the eyes [of the Hen Harrier], technically called the concha, or shell, is brown towards the base of the feathers, but merges into a white eyebrow above, reaching to the cere.
