Zool. [f. TENTACULUM + Gr. κύστ-ις bladder, CYST.] One of the vesicular or cystic tentacles of a hydrozoan, representing a reduced and modified tentacle: see quots. Also TENTACULICYST.
1880. E. R. Lankester, in Nature, 4 March, 414/1. What I have elsewhere termed ‘tentaculocysts,’ modified tentacles which act as auditory organs and have often eye-spots on them as well. Ibid. (1881), in Encycl. Brit., XII. 555/2. Combined visual and auditory organs in the form of modified tentacles (tentaculocysts).
