Note
The male reproductive system, ultrastructure of spermatozoa and spermatogenesis are described for the pleurotomariid Perotrochus quoyanus (Fischer & Bernardi), Gross morphology of the male reproductive system of P. quoyanus agrees in all essential details with that of Mikadolrochus beyrichii. In all features, spermatozoa of Perotrochus quoyanus closely resemble those of Perotrochus westralis Whitehead, 1987, as well as spermatozoa of certain members of the Trochoidea (Trochidae, Liotiidae).