Volume I Part 36 (2/2)

14. BICELLARIA, Blainville.

Character. (B.) Cells turbinate, distant. Opening directed more or less upwards. Mouth submarginal. Several curved spines, marginal or submarginal.

1. B. tuba, n. sp.

Opening round, looking nearly directly upwards; a digitiform hollow process below the outer border supporting 2 to 4 long incurved spines; 2 to 3 other long curved submarginal spines behind or above the opening, none below it in front--a solitary spine on the back a short way down the cell. Avicularia very long, trumpet-shaped, arising on the back of the cell.

Habitat: Ba.s.s Strait, 45 fathoms.

This species is at once recognisable by the remarkable form and unusual position of the avicularium, and also by the peculiar digitiform spiniferous process on the outer side of the opening.

2. B. gracilis, n. sp.

Cells elongated, slender, opening round or suboval, looking obliquely forwards and upwards; three marginal (sometimes slightly submarginal) spines above and behind the opening, and two much longer curved hair-like spines arising from the anterior and lower edge of the opening. Ovicells globose, subpedunculate, attached to the upper and inner part of the margin of the opening. Avicularia small, like birds' heads.

Habitat: Ba.s.s Strait.

A delicate slender species, not unlike B. ciliata or avicularis in habit.

The two long spines arising from the anterior edge of the opening suffice to distinguish it from the former of these two species.

3. B. grandis, n. sp.

Cells much elongated outwards, horizontal or projecting portion oblong, rounded at the extremity; 2 to 5 long curved submarginal spines, externally a single dorsal spine about halfway down the cell; opening oval, narrower outwards; very oblique mouth at the outer end. Avicularia ---- ?

Habitat: Ba.s.s Strait, 45 fathoms.

Quite distinct from B. ciliata not only in its size, which is nearly three times as great, but in the form of the cell and the opening. The number of spines varies very much, and two or three of them, not unfrequently, arise from a common projecting process or base.

4. B. johnstoniae.

Cells obliquely truncated above with a short spine on the outer angle; opening large, suboval, with an obtuse angle outwardly; margin slightly thickened, wholly unarmed.

Habitat: Off c.u.mberland Islands, 27 fathoms, fine grey mud.

Of a light grey colour: grows in large loose tufts, composed of long forked ascending branches. It is a very peculiar species, and some difficulty has been found in finding it a place. In the opening of the mouth, and the external short spine, it is a Cellaria; and in the colour and want of distinct articulation, it approaches Acamarchis; whilst in the form of the cell, and their mode of mutual connection, it is a Bicellaria: it differs from all other species of that genus, however, in the absence of any long spines, and in general habit. Were it not referred to that genus, it would probably const.i.tute the type of a distinct one. A curious little trident-like organ is visible in the narrow part of some cells.

15. ACAMARCHIS, Lamouroux.

Character. (B.) Cells elliptical,* closely contiguous; opening very large, margin simple, not thickened. Avicularia not always present, like birds' heads.

(*Footnote. Viewed posteriorly.)

To which may be added, that the species are frequently coloured, red or bluish.

1. A. neritina, Lamouroux.

Habitat: Rio de Janeiro. Broken Bay, New South Wales.

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