1. Articulata.

Polyzoary divided into distinct internodes by flexible articulations.

a. Internodes elongated, or composed of numerous cells.

Fam. 1. SALICORNARIADAE. Cells disposed around an ideal axis.

9. SALICORNARIA, Cuvier.

a. Surface divided into more or less regular hexagonal s.p.a.ces by elevated ridges.

1. S. punctata, n. sp.

Cellaria salicornioides ? Audoin. Savigny, Egypt. Plate 6 figure 7.

Hexagonal areas with an acute angle above and below; bottom of area pyriform, surface covered with minute transparent granulations. Mouth of cell in the upper third, with a minute tooth on each side.

Habitat: Ba.s.s Strait, 45 fathoms. Off c.u.mberland Islands, 27 fathoms, fine grey mud.

Parasitic upon Sertularians and Polyzoa; branches straggling of irregular lengths.

2. S. bicornis, n. sp.

Areas with an obtuse angle above and below, sometimes rounded above; a minute projection on each side near the top. Bottom of area long-oval, smooth, sometimes with a perforation above the mouth. Mouth with a minute tooth on each side.

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

Parasitic. Branches shorter and thicker than in the preceding species. In the shape of the area they are very much alike, but in S. bicornis, in some cells, and occasionally throughout the greater part of the internode, the area differs widely from the more usual form. It is much expanded, and presents a wide arch above. In this case there is usually a considerable-sized perforation above the mouth of the cell, as occurs not infrequently also in S. farciminoides in the younger cells, and which opening is probably normal, until it becomes filled up by the gradual disposition of calcareous matter. What more especially distinguishes the present from the preceding species are the minute projections on either side at the two upper lateral angles of the hexagonal area, and the smoothness of the surface of the cell. They are both perfectly distinct from S. farciminoides.

b. Surface not divided into distinct areas by raised ridges.

3. S. furcata, n. sp.

Mouth of cell elliptical, occupying two-thirds of its length. Two small perforations on each side immediately above the mouth, protected by a convex transparent hood, which has a rounded opening on its under surface.

Habitat: Prince of Wales Channel, Torres Strait, nine fathoms.

Forms small crowded tufts from one to two or three inches high; branches very regularly dichotomous.

4. S. torresiana, n. sp.

Cell circ.u.mscribed by an acute raised border; opening oval, rather more than half the length of the cell. Cell attenuated below the opening.

Habitat: Prince of Wales Channel, Torres Strait, nine fathoms.

A small broken fragment only preserved; parasitic upon Sertularia mutulata, so that its habit cannot be satisfactorily determined. It is of a greenish colour, but this may be advent.i.tious, although general and uniform throughout the specimen. This species differs from the above in being much larger, and in wanting the two perforations on each side above the mouth--in the less comparative size of the opening of the cell, and in the remarkable elevation of the sharp margin surrounding the upper half of the cell. In the looser aggregation, and in the form of the cells, it shows the transition from Salicornaria to Cellularia.

Fam. 2. CELLULARIADAE. Cells disposed in the same plane.

10. CELLULARIA, Pallas.

Character: (B.) Cells bi-triserial, oblong* or rhomboidal, contiguous.

Opening of cell occupying at least half of the front. Margin thickened, sometimes spinous above. A short spine or a sessile avicularium on the upper and outer angle.

(*Footnote. This shape of the cells is given from the back view of them.)

A. inarmatae--without avicularium.

1. C. monotrypa, n. sp.

Cells oblong, narrowed below, with a single perforation, in the upper and outer part behind. Opening oval, margin smooth; a short spinous process at the upper and outer angle; a sharp short spine in the middle of the upper border of the middle cell, at a bifurcation. Ovicell ? in form of a very shallow excavation in the upper part of the cell in front.

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

The only species with which this can be confounded, is C. peachii (Busk.

Annals of Natural History volume 7 second series page 82 plate 8 figure 1.)

The latter, however, is very much smaller, the cells narrower in proportion to their length, and the margin of the opening minutely verrucose. The cell has more than one posterior perforation; and the central cell at a bifurcation is rounded above and without a spinous process; lastly, the ovicell is much loftier and tesselated on the surface.

11. SCRUPOCELLARIA, Van Beneden.

Character (modified). Cells rhomboidal, with a sinuous depression on the outer and posterior aspect. Each furnished with a sessile avicularium at the upper and outer angle in front, and with a vibraculum placed in the sinus on the outer and lower part of the cell behind. Opening oval, or subrotund, spinous above. Ovicells galeriform.

This natural genus is characterised more particularly by the presence upon EACH cell of a sessile avicularium seated on, or in fact forming the upper and outer angle, and of a vibraculum placed on the back of the cell. The cells in some species are provided with a pedunculate operculum, by which it is intended to designate a process, which arising by a short tube from the anterior wall of the cell, immediately beyond the inner margin of the opening, projects forwards and bends over the front of the cell, expanding into a variously-formed limb, and serving as protection to the mouth of the cell in front. The cavity of the tube by which the process arises, becomes, in the expanded portion, continuous with variously disposed grooves or channels, which terminate at the edges of the operculum. This organ affords excellent specific characters (not in this genus alone). Besides the sessile avicularia above noticed, many species of this genus also possess avicularia of another kind, and which are placed on the front of the cell below the opening and towards the inner side, or in other words, towards the middle line of the branch. In this genus, in all those species in which the second avicularium occurs, each individual cell is provided with one. This additional avicularium appears to be composed of a flexible material, and it is very easily broken off, so that in many instances, perhaps throughout an entire specimen the organ itself may be wanting, although its position is clearly evidenced by the existence of a rounded opening in the usual situation of the organ. It is necessary to distinguish this form of flexible (if such it be) avicularium from the truly articulated and movable avicularia, in the form of birds' heads, and which form does not occur in the genus Scrupocellaria.

a. OPERCULATAE. Cells furnished with a pedunculate operculum.

1. S. cervicornis, n. sp.

Veins or channels in the oral operculum, branching so as to resemble the antlers of a stag. The marginal spine next above the pedunculated operculum, bifurcate.

Habitat: Off c.u.mberland Islands, 25 fathoms, fine grey mud.

A small, delicate, parasitic species, very transparent. The very peculiar markings on the operculum at once distinguish it. The upper margin of the mouth is furnished with five elongated spines, the innermost of which is forked at the extremity.

2. S. diadema, n. sp.

Cells elongate, external side nearly straight, vibraculum sublateral, very prominent. Limit of operculum entire, or obscurely bi-trilobed. A flexible avicularium in front. Ovicell usually with a single row of four or five openings immediately above its mouth.

Habitat: Moreton Bay.

b. INOPERCULATAE. Cells without a pedunculate operculum.

3. S. cyclostoma, n. sp.

Opening of cell nearly or quite circular, margin much thickened, with three or four short indistinct spines above. Vibraculum sublateral. A flexible avicularium in front. Ovicells --- ?

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