Genus Bathyferdina Mah, 2017

[New Japanese name: Koyo-akamon-hitode-zoku]

Diagnosis (emended). Body flat on both sides, disc broad with five short arms. Abactinal plates homogenous in size. Marginal plates significantly larger than abactinal plates, and gradually decrease in size toward the arm tip. Abactinal, marginal, actinal and adambulacral plates covered with skin containing granules. Skin absent on circular or quadrate bare areas on marginal plates. Either or both abactinal, marginal, actinal and adambulacral plates have glassy bosses (crystal bodies) on their surface. Furrow spines arranged in a single longitudinal series. Actinal surface of adambulacral plates covered with skin and granules, but devoid of spinelets, enlarged granules or other accessories.

Remarks. This diagnosis is emended from Mah (2017) to include presence of glassy bosses on actinal and adambulacral plates. For details see remarks under B. caelator sp. nov.

Type species. Bathyferdina aireyae Mah, 2017

Species included. Bathyferdina aireyae; B. caelator sp. nov.