Cris´sum, n. Properly, the under tail-coverts collectively. Oftener used to designate the circumanal plumage. (66.)

Cro´taphyte (depression). A concavity on the outside of the skull on each side behind, filled with muscle; temporal fossa.

Crown, n. Pileus; top of head, especially the vertex.

Cru´cial, Cru´ciform, a. In the shape of a cross. The crucial test is one experimentally conclusive.

Cruræ´us, n. Name of a certain muscle of the thigh.

Cru´ral, a. Pertaining to the crus, or shin.

Crus, n. The shin; segment of the leg between the thigh and ankle, represented by the tibia.

Crys´talline (lens), a. See Lens.

Cu´bit, n. The forearm.

Cu´bital, a. Pertaining to the forearm.