l margin is rounded, protuberant, and of unusual
length compared to the basal margin. The surface of the valve is convex
near the umbo; and beneath there is a large deep hollow for the adductor
muscle.

_Terga_ (fig. 1, _b_) large, flat, triangular, as long as the scuta or
the carina, all three valves being nearly equal in length; occludent
margin straight, or slightly arched, basal angle broad, not very sharp.

_Carina_ short (fig. 1, _c_, drawn rather too long), deeply concave,
rectangularly bent, with the lower part not quite as long as the upper,
and a little wider: the basal margin is truncated, rounded, and slightly
sinuous. The umbo is situated at the angle, and therefore nearly
central. The umbo of the terga, I may add, is in the same place, as in
Lepas.

The _peduncle_ is very short and narrow, and is, I believe, without
spines; it is enveloped by the bark of the Antipathes. The capitulum in
the largest specimens was .2 of an inch in length.

_Filamentary Appendages_, apparently none.

_Mouth_, with the orifice rather inclined abdominally.

_Labrum_, with the upper part extremely protuberant, forming a
projecting horn; no teeth on the crest. Palpi rather small, with only a
few bristles at the end.

_Mandibles_, with four teeth and the inferior angle pointed: first
tooth as far from the second, as is the latter from the inferior angle;
in one specimen, on one side, there were five teeth.

_Maxillae_ with three great spines at the upper angle, beneath which a
deep notch, and with the inferior part much upraised; this lower part
rather rounded at both corners, with the upper spines longer than the
lower.

_Outer Maxillae_, 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 se