erous cell differs widely in form from the others,
being pyriform, and much attenuated below; and the orifice is below the
middle. The upper compartment, in which the ovicell or sac itself is
lodged, appears to be separated from the lower by a transverse diaphragm.

23. DIMETOPIA, n. gen. Table 1 figures 7 to 9.

Cells joined back to back; the mouths of each alternate pair looking in
the same direction, and at rightangles to the intermediate pair.

1. D. spicata, n. sp. Table 1 figure 9.

Cells infundibuliform. Margin of opening much thickened, with six
equidistant, elongated pointed spines.

Habitat: Bass Strait, 45 fathoms.

White, transparent, forming thick tufts about 1 1/2 to 2 inches in
height. The same species also occurs in New Zealand.

2. D. cornuta, n. sp. Table 1 figures 7 and 8.

Cells suddenly contracted about the middle. Opening oval, wide above;
margins slightly thickened with a short thick conical horn on each side
above, and a long projecting spine (rarely two) in front below.

Habitat: Bass Strait, 45 fathoms.

Branches narrower than in the preceding species. Colour yellowish. Tufts
loose; ovicell small in proportion to the size of the cells. It is placed
immediately above and behind the upper margin of the opening of the cell
to which it belongs.

Suborder 3. CTENOSTOMATA.

Fam. 1. VESICULARIADAE. Cells tubular, horny.

24. AMATHIA, Lamouroux.

1. A. biseriata, Krauss. Corall. der Sudsee, page 23. Figure 1 a, b, c.

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 presen