cystidean Geol.
(sɪˈstɪdiːən)
[f. mod.L. cystidea, f. cystis: see cyst and -id.]
= cystid 1.
| 1862 Dana Man. Geol. 398 Cystideans..became extinct in the beginning of the Devonian. 1876 Page Adv. Text-Bk. Geol. xii. 207 So may a cystidean..be considered a sea-urchin attached to the bottom by a similar jointed column. |