Professor MacGillivray on the Cirripedia. 303 
depressions. The mouth very prominent, with an induplicate or some- 
what semilunar, bullate, rounded lip, with two thick, pointed palpi, 
which are adnate, until toward the end, directed forwards and inwards, 
with the tip free, and terminating in a recurved spine, and three pairs of 
incuryate compressed maxillar appendages, lamelliform at the end. 
The first or outer pair, with the terminal lamina oblong, acute, with six 
external, marginal, acuminate, teeth or serratures, of which the poste- 
rior is much larger. The second, with the lamina broad, with four cili- 
ated lobes. The third or inner, less compressed, ciliato-dentate. 
The first pair of feet, oblong, compressed, placed immediately behind 
the mouth, and bearing each a pair of unequal, tapering, compressed, 
horny, articulated, incurvate cirri. The second pair at some distance, 
and the rest close together, subcylindrical, compressed, biarticulate, 
their cirri longer. All the cirri are lobed and ciliate on the anterior bor- 
der, convex on the dorsal side, with a few very small bristles at each 
joint. The first pair with seventeen joints, of which the last five are 
very slender, the last with forty-five joints and lobes, on each of which 
are generally five, or from four to six ciliz on each side, arranged in 
two divergent series. 
On each side, on a prominence at the base of the first foot externally, 
is a long, subulate branchial filament; and at some distance from it, on 
the side of the body, is another about half its length. 
The narrowed part of the body to which the five pairs of abdominal 
feet are attached is marked beneath, and on the sides, with faint trans- 
verse depressions between the feet. It ends in a very long, slender, 
tapering, dusky tube, of about the length of the last cirri. At the base 
of this tube, on the dorsal aspect, is the anus, over which are two ob- 
long, mobile, horny plates. 
The general colour of the body is light brown, or dark yellowish-grey, 
often dotted with dusky; paler on the sides; the cirri dusky brown, 
pale along the back, and with the ciliary bristles brownish-grey. 
The transverse muscle, and subcutaneous muscular layer, as in the 
last species. 
The subsidiary dermal envelope or mantle very thin, dusky-brown, 
margined at the aperture with a yellowish filament. Between it and the 
testaceous tegmen is a film of dark-brown pigment disposed in irregu- 
lar roundish or polygonal fragments. 
The tegmen compressed, tumid below, semicordate, somewhat in- 
curved, with the basal margin convex, the ventral direct, gently sinuate, 
at the end somewhat recurvate, the dorsal uniformly curved in the fifth 
of a circle, the apex obtuse. 
The lower lateral plate considerably convex, subovato-tetragonal, 
very thin, fragile, bluish-white, or greyish-blue, concentrically rugose, 
and faintly striulate, divergently obsoletely striulate ; the basal margin 
convex, the umbonal angle considerably prominent, the ventral margin 
sinuate, the dorsal convex, as long as the basal or longer, the sutural 
margin very slightly convex, the apex acute. 
The upper lateral plate oblongo-tetragonal, flat, somewhat concave, 
very thin, fragile, white, concentrically rugose and striulate, divergently 
obsoletely striulate, the ventral margin straight, or a little concave, less 
than half the length of the sutural, which is slightly concave, the dorsal 
margin convex, with the umbonal point scarcely prominent, its distance 
from the tip less than the length of the ventral margin, the upper angle 
rounded, the lower obtuse. 
The dorsal plate curved, narrow-oblong, convex, with a slight rounded 
carina, striate, narrowed and incurvate toward the base, which is ex- 
