Outer Maxillæ, with the bristles continuous in front; externally, slightly protuberant, with a tuft of bristles longer than those on the front side. Olfactory orifices apparently not protuberant; but all the specimens were in a bad state.

Cirri.—Prosoma very little developed. First cirrus very far removed from the second. The three posterior cirri are straight and long; the segments are elongated and bear four or five pairs of very long spines, with a single minute intermediate spine between each pair; dorsal tufts, with long spines. First cirrus, rami unequal by two or three segments, and thickly covered with spines; the first cirrus is short compared to the second, owing to the length of the pedicel of the latter, though the longer ramus of the first, nearly equals the shorter ramus of the second pair. Second cirrus, with its anterior ramus shorter by two or three segments than the posterior ramus, and thicker than it, with the segments covered like brushes with bristles; posterior ramus, and both rami of the third cirrus, a little more thickly clothed with bristles than are the three posterior cirri.

Caudal Appendages, minute, broadly oval, with six or seven long bristles on their summits.

Genus—Conchoderma. [Plate III.]

Conchoderma. Olfers. Magaz. der Gesellsch. Natuforsch. Freunde zu Berlin, Drittes Quartel, 1814.[34]

Lepas. Linnæus. Systema Naturæ, 1767.

Branta. Oken. Lehrbuch der Naturgeschichte, Th. 2, p. 362, 1815.

Malacotta et Senoclita. Schumacher. Essai d’un Nouveau Syst. des Habitations des Vers., 1817.

Otion et Cineras. Leach. Journal de Phys., vol. lxxxv, p. 67, July, 1817.

Gymnolepas. De Blainville. Dict. des Sci. Nat., Art. Mollusca, 1824.