334 MR. A. HANCOCK ON A BURROWING BARNACLE 
were seen to descend slowly and gradually with their feet spread 
out above, and their back downwards. They seldom or never 
moved horizontally, their chief object apparently being to ascend 
either perpendicularly or diagonally, and always in an inverted 
position, 
On placing a few of these minute beings under the microscope, 
each was found to be provided with a tail, the body being ovate, 
broad and depressed, having on the back an ovate shield tapering 
a little backwards, and with a broad interrupted line of bright 
rose colour towards the margins: it is to this line chiefly that 
the general mass of eggs has a rosy hue, as they approach matu- 
rity. The eye is large, and placed in the centre of the forehead ; 
it is of a very deep rose colour, almost black in some lights. The 
tail is more than half the length of the body, and passes from 
below the shield, and appears to be composed of two or three 
articulations: at first it is very stout ; but, rather suddenly nar- 
rowing, tapers gradually to a tolerably fine point and arches up- 
wards ; on the under surface, at the point of contraction, there 
is a small curved spine. There are three pairs of natatory legs 
placed well forwards, and indistinctly articulated ; the anterior 
pair are simple and furnished with a few long sete, at their ex- 
tremities ; the other two pairs are bifid, the anterior portion 
being much the stouter, and marked with several indistinct 
close-set articulations, towards the extremity; each articulation 
bearing, on its posterior margin, a long seta: the posterior 
branch of the limb is also furnished with set at its extremity. 
On each side of the head, there is a stout process a little arched 
backwards, with the point obtuse; these I am inclined to look 
upon as antenne, for they appear to arise from the head beneath 
the shield, though this could not be determined with certainty. 
It is possible enough that they are lateral prolongations of the 
shield, similar to the “ anterior horns ” of the larva of the pedun- 
culate Cirripedes. Whether so or not, the larva of this new 
animal may at once be distinguished from that of this division 
of the Barnacles, by the absence of the long spine projecting from 
the posterior margin of the shield. In other respects, it evidently 
shows a strong general resemblance to the larva of these animals, 
