Habitat: Swan Island, Banks Strait.
The biserial arrangement of the cells is not a sufficient character, because in Amathia cornuta (Lamouroux) the cells are also biserial as well as in another South African species, very like the Australian form probably intended by Krauss, but apparently different from it. In the South African form the cells are shorter, narrower, and more cylindrical, and the branches are terminated by two lanceolate tags, which are not present in the Australian species, in which latter the cells also are wider, longer, and prismatic, or subhexagonal, with very thin walls.
SERTULARIAN ZOOPHYTES.
The number of species of Sertularian Zoophytes comprised in this collection amounts to thirty-one, belonging to five genera, all of which appear to be common to both the Northern and Southern hemispheres; and four are European types. The fifth, Pasythea, is stated by Lamouroux, to be found on Fucus natans and in the West Indies; so that the present collection does not present any peculiar Australian generic form. It is far otherwise, however, with respect to the species. Of these three only are found in the European seas namely:
Sertularia operculata.
Campanularia dumosa.
Campanularia volubilis ?
Of which the first is a perfect cosmopolite, and the last is perhaps doubtful.
There are also, what is much more strange, not more than three species which I have been enabled to trace to any other locality, even in the Southern hemisphere. These are:
Sertularia elongata.
Sertularia divaricata, n. sp.
Plumularia macgillivrai, n. sp.
The first occurring in New Zealand; the second on the south coast of Patagonia and in the Straits of Magellan; and the third (which, however, is not, strictly speaking, an Australian form, having been procured in the Louisiade Archipelago) in the Philippine Islands. With these six exceptions, the whole number of species would therefore, to a certain extent, appear to be characteristic of the Australian seas.