Twenty species of Acanthomysis s. l., distributed in Japanese, Korean and Chinese coastal waters, arerevised. These species are distinguished from Acanthomysis s. str. by the following characters: thecarpopropodus of the endopod of the third to eighth thoracic limbs divided into three to eightsubsegments; the exopod of the fourth male pleopod with two long subequal terminal setae; the telsonlong linguiform or triangular without basal dilated portion and armed with spines throughoutmargins. On the basis of these characters, the genus Orientomysis, which was revived by Holmquist(1981b) and comprised O. japonica and O. mitsukurii, is redefined and recognized to contain thefollowing 18 valid species: O. aokii, O. aspera, O. crassispinosa, O. fujinagai, O. hwanhaiensis, O.koreana, O. leptura, O. meridionalis, O. okayamaensis, O. pseudomitsukurii, O. robusta, O. rotundicauda,O. sagamiensis, O. serrata, O. sheni, O. tamurai, O. tenella, and O. tenuicauda. Acanthomysis longicauda and A. nakazatoi are synonymized with O. rotundicauda and O. japonica, respectively. A new species, O. arenaria, is described from Japan. |
