Sentence:  The first reference to the internal anatomy of species of "Cassidula" was by Odhner (1925), who divided the Ellobiidae H. and A. Adams in Pfeiffer, 1854, into two large groups, on the basis of the <WSD>aulic</WSD> condition of the pallial gonoducts. 
Meaning of the word marked with <WSD> tags:  Pertaining to the reproductive ducts of certain organisms.