A new genus, Halorosellinia, is introduced to accommodate the lignicolous m
angrove inhabitant Hypoxylon oceanicum. A detailed illustrated account of t
he teleomorphic and anamorphic states is given. Halorosellinia oceanica com
b. nov., is compared with Stilbohypoxylon quisquiliarum and Nemania conflue
ns (a reduced form of Nemania) and the reasons for introducing a new genus
are discussed. Data on the ecology and geographical distribution of H. ocea
nica are presented.