A list of species in the collection is given. Six of these are already known from the Antarctic. One species, Hansenomysis antarctica Holt and Tattersall, 1906, previously known only from two types and two other isolated specimens, all of which lacked the posterior region of the telson, is represented by a complete specimen and the tail-fan is fully figured and described. A species of the same genus, new to science, is described and figured; the genus is reviewed, the homology of certain organs discussed and a key for the identification of its known species given.