Narrative of the Voyage of H.M.S. Rattlesnake Volume I Part 34

Habitat: Ba.s.s Strait? This species also occurs in New Zealand.

Colour brown, loosely branched and several inches high. Distinguished readily by the cribriform aspect of the front of the cell, and by the curiously formed central orifice, and by the absence of any superior appendage to the avicularium.

b. Vittatae.

Cells furnished with a narrow elongated band or vitta on each side, without fenestrae. Ovicells not terminal, galeriform.

8. C. formosa, n. sp.

Cells oval; avicularia large, flat, or cupped above. Vittae elliptical, rather anterior.

Habitat: Swan Island, Banks Strait.

Colour light plumbeous. Parasitic upon C. margaritacea. The cells are the largest of any in the Vittate division, and very regular and uniform in size and outline. The more distinctive characters are taken from the comparatively broad vittae, and the flat or cupped upper surface of the avicularia, which are usually continued downwards into a prominent ridge or ala.

9. C. gibbosa, n. sp.

Cells pyriform, ventricose posteriorly, much attenuated at bottom.

Avicularia small, placed in front close to the sides of the mouth, at the base of strong conical pointed processes which project in front, and are connected across the top of the cell by a prominent toothed ridge. Vittae long linear, entirely lateral.

Habitat: Prince of Wales Channel, Torres Strait, 9 fathoms, mud.

Of a dark lead colour, when dry. Forms an elegantly branched bush about two inches high. The gibbous form of the cells, and the peculiar anterior position of the avicularia, at the base of the projecting lateral processes, at once distinguish it from all the other vittate species. The toothed (sometimes entire) ridge extending between the two lateral processes across the top of the cell and overlapping the mouth like a penthouse is also a very peculiar feature.

10. C. elegans, n. sp. Table 1 figure 2.

Cells elongated ovoid; avicularia large and projecting, without any superior appendage; vittae narrow, rather anterior.

Habitat: Ba.s.s Strait, 48 fathoms. Port Dalrymple, on stones at low water.

A delicate and beautiful parasitic species; the branches slender and spreading; colour white and very transparent. Cells regular and uniform in size and shape. A very similar if not identical species occurs in Algoa Bay, South Africa, the only difference between them being that the latter is rather larger and has the vittae much longer; in the Australian forms these bands do not reach above the middle of the cell, whilst in the South African they extend as high as the mouth.

11. C. cornuta, n. sp.

Cells oval; avicularia in many cells wholly transformed into long pointed retrocedent spines, on one or both sides, in others into shorter spines or unaltered. Vittae linear, extremely narrow, entirely lateral, and extending the whole length of the cell from the base of the avicularium.

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

Colour yellowish white, growth small; parasitic upon C. amphora. As some difficulty might be experienced in the discrimination of this species from C. elegans, and another South African species (not the variety of C.

elegans above noticed) it is requisite to remark that the long retrocedent spines when present are not placed upon or superadded to the avicularia, but that they seem to represent an aborted or transformed state of those organs. They vary much in length and size in different cells, and even in those of the same branch; as it frequently happens that there is a spine, usually of diminutive size, on one side and a very large avicularium on the other, and sometimes (but rarely) an avicularium of more moderate size on both sides. But the character of the species by which it is more particularly distinguished consists in the presence on a great many cells, in one part or other of the polyzoary, of the two large and strong spines projecting BACKWARDS. This retrocession of the spines is alone a sufficient character to distinguish the present species from the South African form above alluded to (C. taurina, B.) And the length and lateral position of the vittae would distinguish the unarmed cells from those of C. elegans.

12. C. umbonata, n. sp.

Cells more or less pyriform, alate, narrow below, bulging or ventricose upwards. Avicularia large and strong. Vittae strap-shaped, anterior, extending from the level of the mouth to the bottom of the cell, with elevated ac.u.minate papillae or short spines. A broad compressed projecting process on the middle of the back.

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

The cells in this species are small, inflated or ventricose, and as it were sub-globular above, becoming much attenuated below--but the cavity of the cell does not appear to extend into this contracted portion, in which is contained the connecting tube strengthened by calcareous matter--the inferior continuation of the lateral alae, which descend from the base of the avicularium. Owing to the large size of the avicularia, the upper part of the cell is much widened, and the whole acquires somewhat of a triangular form, and has a peculiar rugose aspect, derived, in part also, from the large size and elevation of the ac.u.minated papillae, not only of the vittae but on the surface of the cell itself.

The central umbo or crest posteriorly is a marked feature.

c. Without vittae or fenestrae.

13. C. carinata, n. sp.

Cells oval, narrowed at both ends; lateral processes (without avicularia ?) projecting horizontally upwards from the sides of the mouth about the middle of the cell. Mouth nearly central, with a small tooth on each side, and below it a triangular s.p.a.ce with three strong conical eminences. The cell which bears the ovicell geminate.

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

This remarkable form differs so widely in many respects from any of its congeners, as almost to deserve to be considered as the type of a distinct sub-genus. The lateral processes, which may be taken to represent the perfect avicularia of the other species, are, as far as can be ascertained from specimens that have been dried, without a movable mandible, and are probably really so, because there is no corresponding beak. These processes are channelled in front, nearly from the base to the extremity; they arise by a broad base on each side of the mouth, and on the front of the cell, and from the conjoined bases is continued upwards and downwards, or to the top and bottom of the cell, a prominent flattened band. The expanded bases circ.u.mscribe an oval s.p.a.ce, nearly in the centre of the front of the cell, the upper two-thirds of which s.p.a.ce are occupied by the circular mouth, on each side of which is a small calcareous tooth, to which apparently are articulated the horns of the semilunar lateral cartilage. The lower third is filled up by a yellow, h.o.r.n.y (?) membrane, upon which are placed three conical eminences, disposed in a triangular manner. The back of the cell is very convex, and has running along the middle of it an elevated crest or keel, which is ac.u.minate in the middle. The ovicell is situated in front of the cell below the mouth, and below it are three considerable-sized areolated spots, disposed, like the three conical spines, in a triangle. The cells upon which the ovicells are placed are always geminate, that is to say, have a smaller cell growing out from one side.

6. Calpidium, n. gen. Table 1 figures 3 to 5.

Character: Cells with an avicularium on each side; with two or three distinct mouths, arising one from the upper part of another, in a linear series, all facing the same way, and forming dichotomously-divided branches; cells at the bifurcation single; ovicells ---- ?

This very peculiar genus, remarkable as it is, seems. .h.i.therto to have escaped notice. It is distinguishable from Catenicella, in the first place, by the anomalous circ.u.mstance that each cell is furnished with two or more, usually three, distinct keyhole-shaped mouths, and is doubtless inhabited by three distinct individuals. Whether these are separated from each other by internal part.i.tions is unknown, but the closest examination of cells rendered transparent by means of acid fails to discover such. In cells thus prepared, there are apparent, however, three distinct ma.s.ses, reaching from the bottom of the cell to each orifice, and which are probably the remains either of the body or of the retractor muscles of the animals. Another point of difference from Catenicella is the non-gemination of the cell at the dichotomy of a branch. The avicularia, moreover, do not form lateral projections, but are sessile, or imbedded, as it were, in the sides of the cell immediately below the upper angles.

1. C. ornatum, n. sp. Table 1 figures 3 to 5.

Cells triangular-urn shaped, very broad above, with a straight border, much compressed; mouths, 2 to 3, keyhole-shaped. Five fenestrae below each mouth; numerous branching bands on the back of the cell.

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

This curious species is the only one belonging to the genus. The cells are very large, regular, and uniform, resembling very closely an antique sculptured urn. Colour dark brown, and the walls so thick as to be nearly opaque. The polyzoary, which appears to attain a height of four or five inches, is bipinnate (with all the branches on one plane) the branches alternate, and given off with extreme regularity. The ultimate ramules are incurved. The whole forms a very elegant object. The central stem, or series of cells, differs in no respect as regards the size or disposition of the cells composing it, from the branches.

Fam. 2. EUCRATIADAE.

7. EUCRATEA, Lamouroux.

1. Eucratea chelata, Lamouroux.

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

In all respects identical with the British form. It also occurs at Port Adelaide.

8. ANGUINARIA, Lamarck.

1. A. spatulata, Lamarck.

Aetea anguina, Lamouroux.

Habitat: Ba.s.s Strait, and other localities.

This species (which appears to be pretty generally distributed over the globe) is identical with the European form. It is to be remarked, however, that a second species (A. dilatata, Busk. Annals of Natural History second series volume 7 page 81 plate 9 figure 14) is found in Torres Strait, but which does not occur in the Rattlesnake collection.

-- 2. MULTISERIALARIA. Cells disposed alternately in a double or multiple series.