Deep-sea bamboo corals (Family Isididae: subfamily Keratoisidinae) are a widely distributed group of gorgonian octocorals, commonly found in the deep sea below 200 m, with the deepest specimen to date collected at 4700 m. Two specimens were collected from the seamounts off Tasmania at depths of 3065 to 3950 m. In situ high-definition images, compound microscopy of preserved specimens, and Scanning Electron Microscopy (SEM) provided morphological data on distinguishing morphological characters such as colony shape and branching pattern, polyp arrangement, composition of the axial skeleton, and shape and arrangement of the sclerites. The genus Bathygorgia Wright, 1885 is resurrected and distinguished from Keratoisis, and two new species, B. abyssicola and B. tasmaniensis are added.