The Collaborative International Dictionary
Trochosphere
Trochosphere \Troch"o*sphere\, n. [Gr. ? a wheel + sphere.] (Zo["o]l.) A young larval form of many annelids, mollusks, and bryozoans, in which a circle of cilia is developed around the anterior end.
Wiktionary
trochosphere
n. (context zoology English) A young larval form of many annelids, mollusks, and bryozoans, in which a circle of cilium is developed around the anterior end.