Cirrhipedes. Ten genera.

Lamarck divided the Lepas of LinnÆus into the various genera which compose this family. The term lepas is derived from the Greek word ?epa?, a rock, alluding to its custom of adhering to rocks and marine bodies. The shell often varies in shape, covering, and colouring; it is generally conical, but sometimes hemispherical; some of the valves are placed perpendicularly on a base, broad at the lower margin and tapering towards the summit, which is closed by small horizontal valves forming the operculum. The number of valves is indefinite, from four to twenty-four; but all are diversified with striÆ, ridges, and grooves. The striÆ are mostly transverse, and the ridges longitudinal.

The valves which compose the operculum or lid vary in shape, and are in number two, three, four, or more; they are generally attached to a ligament.

They are seldom, if ever, found detached, but adhere in groups to rocks, shells, anchors, marine animals, &c. Those that fix themselves to ships are generally called barnacles; they rapidly increase in size and number, do great damage, and greatly impede the progress of the vessel. Some of this family are affixed at the base of the shell to other substances, and are therefore called sessile; others are attached to a fleshy peduncle or stem, and are said to be pedunculated. The peduncle or stem, proceeding from the base of the shell to the substance which sustains it, is sometimes smooth, fine in texture, and tinged with bright red or orange; sometimes it is of a dark or brownish colour, with a texture much coarser and granulated.

1. Tubicinella. One species.

Has the form of a cylindrical tube, slightly curved, and open at both ends; one extremity closed by four trapezoidal valves attached to the inner margin, the other end closed by a membrane. The annular ribs which separate the compartments show its progressive growth. Found buried so deeply in the fat of marine animals, particularly whales, that only the operculum and the upper part of the tube are visible. Shell rather elevated, sub-cylindrical, the partitions rather small and indented; the spaces or compartments almost quadrilateral; the inferior much more narrow than the others; the apertures equal and circular; the membrane which closes the superior forming a tube between the four almost equal valves of the operculum.

T. balÆnarum. The Whale Tubicinella.

Tubular, with transverse ribs, and a ring-shaped margin; operculum bottle-shaped.

2. Coronula. Three species.

Found imbedded in the skin of whales and other marine animals, though not generally at so great a depth as the Tubicinella. Shell in form a little variable and without trace of support; the coronary part formed of six pieces, as in those properly called Balanus, but more regularly disposed in a manner to imitate a kind of crown or tube; spaces alternately hollowed and saliant; operculum not articulated, composed of two pairs of small, level, delicate valves, joined at the aperture of the tube by a considerable membranous part, leaving a passage for the cirrhous appendages of the animal.

C. testudinaria. The Tortoise Coronula.

Very depressed, circular, as if radiated by the disposition of marked spaces, striated transversely, forming six rays diverging from the centre to the circumference; aperture oval and hexagonal.

C. balÆnarum. The Whale Coronula.

A little more elevated; the spaces prominent, equal between them, much larger than the excavated; the aperture subcircular; the operculum of four valves, almost equal, occupying but a small space of the membranous part which forms between them a sort of tube.

C. diadema. The Crown Coronula.

More elevated, sub-hexagonal; the spaces almost equal, the hollow parts larger than the saliant; the superior aperture very large and hexagonal; the inferior much smaller, of the same form, and communicating in a round excavation by radiated plates; the operculum bivalve.

C. quinquevalvis. The five-valved Coronula. Pl. 4, fig. 3.

Species irregular, having only five valves, of a purple hue.

3. Balanus. The Acorn Shell. Twenty-eight species.

So named from its resemblance to an acorn. Shell conical; the coronary part formed of six very distinct valves, one dorsal, one ventral, and two pairs of laterals, with or without a calcareous support; operculum of four articulated pieces, forming a sort of pyramid in the superior aperture of the tube.

B. sulcatus. The furrowed Balanus.

White; valves nearly smooth; operculum strongly ridged transversely, with longitudinal, nearly obsolete striÆ.

B. tintinnabulum. The little Bell Balanus. Pl. 4, fig. 1.

Shell conical; valves strongly and irregularly ribbed; interstices delicately striated transversely; colour purple.

B. spinosus. The spiny Balanus.

Either has no support or a membranous one; armed with spines exteriorly.

4. Acasta. Three species.

Found in sponge, from which, when detached, it cannot stand erect on account of the convexity of the base.

Shell oval, sub-conic, shaped like a Patella, with six lateral unequal valves slightly connected; operculum with four valves.

A. Montagui. Montague’s Acasta.

Valves erect, triangular, acute, with muricated ascending spines.

5. Creusia. Three species.

The shells of this genus are generally small; found in the seas of hot countries attached to madrepore and other marine substances.

Shell sessile, thin, Patella-shaped; aperture oval, rather large, closed by a large sub-pyramidal bivalve operculum; a considerable calcareous support, funnel-shaped, penetrating the bodies to which the animal is attached.

C. spinulosa. The spiny Creusia.

Very depressed, striated, sometimes with marks of division into four pieces; operculum bivalve.

C. verruca. The warted Creusia. Pl. 4, fig. 2.

Whitish, slightly depressed, with interwoven obliquely striated valves; the margin at the base irregularly serrated.

6. Pyrgoma. One species.

The principal difference between this genus and the Creusia is in form.

Shell sessile, rather globular appearance on account of the valves being more closely united, ventricose, convex above, apex perforated, aperture small and elliptical; operculum bivalve.

P. cancellata. The cancellated Pyrgoma.

Thick, conical, Patella-shaped, ribs radiating from the summit to the base; aperture very small, closed by an operculum of which the two pieces are long and narrow on each side; pale violet colour.

7. Anatifera. Five species.

The shells of this genus and the three following genera are affixed to marine bodies by a tough membranous peduncle, varying in length.

Shell flat, with five valves imbricating more or less on the edges, united by a thin membrane.

A. lÆvis. The smooth Anatifera. Pl. 4, fig. 5.

Five smooth valves; the dorsal one rounded at the sides, and slightly carinated; peduncle long, naked, of a scarlet colour.

8. Pollicipes. Three species.

Easily distinguished by the numerous small valves situated at the base.

P. cornucopia. The Cornucopia Pollicipes. Pl. 4, fig. 6.

Peduncle covered with imbricated scales, the lower ones rounded and turned upward.

P. mitella. The Mitre Pollicipes. Pl. 4, fig. 4.

Valves indefinite in number, from six to twenty-four; almost equal, and open like tulips; colour bluish, purplish, brownish, or reddish cast.

9. Cineras. One species.

Shell composed of five testaceous oblong valves, separate, not covering the whole of the body; two at the sides of the aperture, the others on the back; peduncle of a greenish colour, with six longitudinal stripes.

C. vittata. The filleted Cineras.

Answers to the above description.

10. Otion. Two species.

Shell composed of two testaceous valves, enclosed in a mantle or membranous bag, which is prolonged and terminated in two fleshy tubes formed like ears, one of the two having a lateral opening.

O. Cuvierii. Cuvier’s Otion.

Answers to the above.

O. Blainvilli. Blainville’s Otion.

Ash coloured; the body and ears spotted with black.