The Collaborative International Dictionary
Ascidiarium
Ascidiarium \As*cid`i*a"ri*um\, n. [NL. See Ascidium.] (Zo["o]l.) The structure which unites together the ascidiozooids in a compound ascidian.
Wiktionary
ascidiarium
n. (context zoology English) The structure that unites the ascidiozooids in a compound ascidian.