The Collaborative International Dictionary of English v.0.48:
Amphineura \Am`phi*neu"ra\, n. pl. [NL., fr. 'amfi` + ? sinew, nerve.] (Zool.) A division of Mollusca remarkable for the bilateral symmetry of the organs and the arrangement of the nerves. [1913 Webster]WordNet (r) 3.0 (2006):
Amphineura n 1: a class of Gastropoda [syn: Amphineura, subclass Amphineura]