Habitat: off Cumberland Islands, 27 fathoms fine grey mud.
Colour white or yellowish; forms close rounded tufts 2 1/2 to 3 inches in height and width, composed of uniform dichotomously divided branches, about 1/8 of an inch wide, and which become wider towards their truncate extremities. The vibracula are very large, and though distinctly defined, are yet sufficiently transparent to allow a view of the lozenge-shaped cells. The central rows of cells vary in number from two to five, and the cells composing them are arranged with extreme regularity. The marginal rows are placed in a plane posterior to the central, and as above noticed, the cells of which they are composed are widely different from the central.
The only other species with which the present can be confounded is Caberea hookeri (Cellularia hookeri, Fleming) a British form. The latter species appears to differ from C. lata, chiefly in its having a large tubular spine on each side of the mouth of the lateral cells, and in each of the central cells, or nearly so, being furnished with an anterior avicularium, below the opening and to one side. The lateral sessile avicularium on the marginal cells is also much larger.
Fam. 5. FLUSTRADAE.
Polyzoarium expanded, continuous or encrusting. Cells disposed in straight series, which do not radiate from a centre.
17. Flustra, Linn.
a. Cells on one side only.
1. F. pyriformis ?, Lamouroux.
Cells pyriform, or barrel-shaped, prominent, marked with transverse wrinkles. Ovicells lofty, keeled in front, with a strong central, and two lateral longitudinal ribs.
Habitat: Bass Strait, 45 fathoms.