Defn: One of the Cystidea.

CYSTIDEA
Cys*tid"e*a (ss-td"-), n. pl. Etym: [NL., fr. Gr. (Zoöl.)

Defn: An order of Crinoidea, mostly fossils of the Paleozoic rocks. They were usually roundish or egg-shaped, and often unsymmetrical; some were sessile, others had short stems.

CYSTIDEAN
Cys*tid"e*an (-td"-an), n. (Zoöl.)

Defn: One of the Cystidea.

CYSTINE
Cyst"ine (ss"tn; 104), n. Etym: [See Cyst.] (Physiol. Chem.)

Defn: A white crystalline substance, C3H7NSO2, containing sulphur, occuring as a constituent of certain rare urinary calculi, and occasionally found as a sediment in urine.

CYSTIS
Cys"tis (ss"ts), n. Etym: [NL.]

Defn: A cyst. See Cyst.

CYSTITIS
Cys*ti"tis (ss-t"ts), n. Etym: [Cyst + -itis: cf. F. cystite.] (Med.)