Development of Lycaea Pulex Marion, 1874 and Lycaea vincentii Stebbing, 1888 (Amphipoda, Hyperiidea)

The development of Lycaea pulex Marion, 1874 is described and compared with that of L. vincentii Stebbing, 1888. The two species differ in three respects—the shape of the male first antenna, the absence of serrations on pereopod 5 in L. pulex, and in the proportions of the first uropods. Lycaea pulex does not have a specialized larval stage, as does Brachyscelus crusculum Bate, 1861 which was thought to be closely allied. The Lycaeidae seem to occupy an intermediate position between the Oxycephalidae and other families of the Platysceloidea.