[3] The species was identified by Wise in 1958, based on a specimen collected from Waitati in 1917 by C. E.
[5][6] Patrick confirmed that the species was distinct from other members of Olinga, based on behavioural differences and the apparent inability to hybridise with O.
[5] Wise's original text (the type description) reads as follows: ANTERIOR WING fuscous; scales of longitudinal fold and sub-terminal furrow ochreous, Membranes of both anterior and posterior wings fumose.
Dorsal portion of ninth segment produced downwards posteriorly with upper penis-cover in form of two short processes arising distally below.
[5] Wise noted that the species was visually similar to O. feredayi, but could be identified by O. fumosa being smaller, darker in colour, differences in genitalia and the seventh sternite.