SIX SPECIES OF THE SUBFAMILY CYTHERURINAE MULLER, 1894, IN THE INLAND SEA, JAPAN (OSTRACODA)

Abstract

This paper deals with six species of the subfamily Cytherurinae Muller, 1894, in the Inland Sea: viz., three Hemicytherura and three Semicytherura species, with special reference to the description of two new semicytherure species and appendages of hemicytherure and semicytherure species. As regards Hemicytherura, three recent species have hitherto been reported from Japan, which also occur in the Inland Sea. Semicytherura is established by Wagner ( 1957) for cytherure species possessing the conspicuously wide infold and fused zone, and the crenulate median hinge-element. Hanai (1957), scrutinizing valves of Japanese Semicytherura (then, a part of Cytherura) species, has indicated that they may be divided into at least two groups: namely, the second group of Milller (1894) represented by S. miurensis and a new group characterized by thick valves with undulated ridges, comprising S. henryhowei (=C. quadrata, then). Examining semicytherure species in the Inland Sea reveals that two groups are different also in appendages. The groups are named miurensis-group and henryhowei- group and described here. I wish to express my thanks to Prof. A. Inaba of Hiroshima University and Prof. T. Hanai of the University of Tokyo for their invaluable advice.