[Excerpt from first page]: On this account the main interest of the present Report lies in the additional information which it offers regarding the morphology of species of great rarity, and regarding the variations of structure to which these, and the more widely distributed forms here represented, are subject. The characters of several of the specimens are so distinct from those recorded that I have found it necessary to establish for them eight new species, and varieties, distributed amongst the genera Lictorella (1 sp.), Cryptolaria, (1 sp. and 2 vars.), a genus not hitherto known from the Australian area, Sertularella (1 sp. and 1 var.), Halicornaria (1 sp.), and Cladocarpus (?) (1 sp.), also recorded for the first time from Australia. Of these the most interesting, from a general point of view, is the dimorphic variety of Cryptolaria crassicaulis, which throws light on the phylogenetic origin of Cryptolaria, and emphasises the close relationship that exists between that genus and Lafoëa. The gonosome of the widely distributed Lafoëa serrata has been described for the first time. The comparative rarity of Gymnoblastic forms and of minute epizoic species is noticeable.