Re-description of Heterodesmus adamsii Brady, 1866 from Japan,with a description of a new congeneric species (Ostracoda: Myodocopina)

Heterodesmus adamsii Brady, 1866 from Amakusa and a new species, Heterodesmus apriculus sp. nov. from Amakusa and Noto, both from Japan are reported. It is confirmed in the present study that the main characteristics of the carapace and appendages of H. adamsii accord with those of the genus Amphisiphonostra Poulsen, 1962, and it is concluded that the latter is a junior synonym of Heterodesmus Brady, 1866. A diagnosis of the genus Heterodesmus is given.