308 Mr. A. Hancock on a Burrowing Barnacle 
this body is composed of the upper lip, which differs considerably 
from that of the other Cirripedes. In this it is delicate and 
horny, being enormously developed and surmounted by a sort of 
rostrum (figs. 6 & 7 g & h), which projects upwards and forwards 
and terminates in a slightly produced obtuse point ; the dorsal 
margin (fig. 7c) is carinated and minutely denticulated. There 
are three pairs of mandibles as im the other Cirripedes : the outer 
pair, f, are each apparently composed of three articulations, the 
third or terminal one being much compressed, forming an irre- 
gular oval plate, with the upper end terminating in a tooth-lke 
process curved inwards; the two other articulations are much 
narrower, but on account of their minuteness and delicacy their 
form could not be determined with accuracy. Only two articula- 
tions were observed in the second pair of mandibles, g ; the imner 
or first articulation is long, thin and straight, with the extremi- 
ties enlarged, and of an irregular form ; the outer or second joint 
is very similar to that of the outer pair; it is however provided 
with two incurved teeth or spine-like processes at the upper ex- 
tremity. The innermost or third pair of mandibles, /, are rather 
wide, squarish plates with three or four stoutish hairs on their 
upper margin. 
At each side of the mouth there is a stout arm or palp (fig. 6 / 
& fig. 7 dd) which stands erect and reaches a little above the 
ridge of the rostrum ; the anterior margin of these arms is a 
little convex, the posterior a little concave; and they are fur- 
nished with stout, rather soft pincers about half the length of 
the arm, covered with numerous long hairs: at the root of the 
pincers there is an articulation, so that they can be either bent 
forward or carried erect ; there is also apparently an imperfect 
joint at the point where the arm joins the side of the mouth, but 
this could not be determined with certainty, as the horny mem- 
brane of the limb is so delicate that it is impossible to say whe- 
ther the occasional flexure at this part is owing to its flexibility 
or to an articulation. It is difficult to say whether these arms 
represent what Dr. Martin-Saint-Ange names the jaw-feet im 
the pedunculate Cirripedes, or the two minute processes that 
are closely attached to the sides of the mouth in these animals, 
and which are considered palps by some writers. They seem to 
occupy the place of the latter, though from their form they have 
much the appearance of rudimentary anterior feet of the higher 
Crustacea. 
On each side of the rostrum, extending backwards and a little 
way below the carinated ridge, there is a series of rather close- 
set, transverse plates or hairs (figs. 6 & 777) which taper towards 
their points, and are stout at their origin, where they are slightly 
ae’ = 
