Biology and comparative anatomy of Divariscintilla yoyo and D. troglodytes, two new species of Galeommatidae (Bilvalvia) fromstomatopod burrows in eastern Florida

Two new galeommatid bivalves, DivariscintiJla yoyo and D. troglodytes, are described ascommensals in burrows of the stomatopod Lysiosquilla scabricauda from central eastern Florida.They are remarkable in their snail-like appearance and behavior, due to elaborately ornamentedpallial layers enclosing the shell, and their ability to actively crawl on a highly mobile foot.Both are simultaneous hermaphrodites, brooding their larvae in the suprabranchial chamberprior to release of straight-hinged veligers. The two new species differ from one another in shellmorphology, the number of secretory "flower-like organs," and the nature and ornamentation ofthe mantle. They differ from the type and only other described species in this genus, D. maoria,primarily in shell characters, namely in anterior (rather than posterior) prolongation, and in theabsence of a ventral cleft.