Cells oval or sub-globular, much compressed; avicularia short and broad, supporting a deep cup-like cavity. Fenestrae 5, large. Lower margin of mouth notched in the middle; back of cell minutely sulcated; sulci short, interrupted, and irregular. A small lateral area.
Habitat: Swan Island, Banks Strait.
A very beautiful species, the branches resembling strings of minute pearls. The pearly lustre (in the dry state) owing without doubt to the minute sulci on the backs of the cells. These sulci are not, however, consequent upon the drying, because they are equally apparent and constant when the specimen has been immersed in fluid. The species may almost at once be distinguished by the notch in the lower margin of the mouth, which notch represents the central suboral opening present in some other species.
4. C. ventricosa, n. sp. Table 1 figure 1.
Cells oval, compressed, rather wide below; avicularia wide, supporting sometimes a cup-like cavity, sometimes a closed broad conical spine. The prehensile part of the avicularium itself small, seated in a deep notch below the acuminate summit; lateral area large and well defined. Fenestrae 7, with fissures radiating to a rounded central opening. Anterior surface of cell studded with minute acuminate papillae; posterior surface smooth, sometimes spotted.
Habitat: Bass Strait, 45 fathoms.
Colour dirty white or brown. Habit stiff, stem strong, straight, branches short and crowded--probably attains a height of four or five inches. The only other species with which it can be confounded is C. amphora, from which it differs in the greater size and more irregular form of the lateral processes, in the presence of the minute papillae on the surface, and in the absence of the narrow longitudinal band on the back; instead of which the older cells in C. ventricosa exhibit a sort of broad scutum, almost covering the back of the cell and sending off two lateral bands on the sides of the cell, one passing below the avicularium and above the lateral area, and the other towards the acuminated apex of the avicularium. It also wants the raised bands which in C. amphora pass from the sides of the mouth to the apex of the avicularium in front. One large specimen presents a variety worthy of note--in this the backs of all the cells, except one here and there, exhibit (internally ?) numerous irregular-sized leopard-like spots.
5. C. plagiostoma, n. sp.
Cells short-ovoid; avicularia very large and long, ascending from near the bottom of the cell into an acute spinous point, and supporting a deep cupped cavity; mouth placed obliquely; front of cell divided into five large subtriangular fenestrae by four broad bands. Back of cell with a broad central band and two narrower bands branching from it on each side; surface of spaces left uncovered by the bands on the back beset with scattered, long setose spines.
Habitat: Bass Strait, 45 fathoms.