Mesolamprops japonicus (Zimmer, 1937) Lamprops (?) japonicus Zimmer, 1937: 42, figs 8–10.— Lomakina, 1958a: 94, fig. 41. Mesolamprops japonica Tsareva, 1999: 431–433, figs 1–3. Type material. Holotype: male. Deposition unknown. Not seen. Diagnosis. Carapace without lateral ridges, dorsal crest entire. Pleon not including telson equal to carapace and pereonites together. Telson with 2 pairs lateral setae, 5 terminal setae, outer pair longest, inner pair short. Adult male antennal flagellum long, extending to end of pereon; pleopod rami unequal, uniarticulate, lateral ramus smaller than medial ramus. Depth. 10–63 m. Distribution. Tatarsk Strait; Peter the Great Bay, Sea of Japan, 42°40’N, 131°50’E. Remarks. Lamprops japonicus was redescribed by Tsareva, 1999, with complete descriptions of males and females, and referred to Mesolamprops. The most similar species is M. bispinosus, which can be differentiated by the pleon length. In M. bispinosus the pleon (not including the telson) is shorter than the carapace and pereonites together, while in M. japonicus the pleon (not including the telson) is longer than the carapace and pereonites together.

Published as part of Gerken, Sarah, 2018, The Lampropidae (Crustacea: Cumacea) of the World, pp. 1-192 in Zootaxa 4428 (1) on page 94, DOI: 10.11646/zootaxa.4428.1.1, http://zenodo.org/record/3769771