312 Mr. A. Hancock on a Burrowing Barnacle 
multitude of very long sete arranged in double rows along the 
surface next the niouth. These sete diverge, so that when the 
cirri are spread out, the tips of the sete of the adjoining cirri cross 
each other, making a very complete net which the Cirripede is for 
ever spreading out and sweeping through the water in the direc- 
tion of the mouth. Its prey is thus secured, and nothing can 
escape that comes withm the range of this simple and beautiful 
apparatus. It is not then by currents produced by the cirri, as 
usually asserted, that these creatures obtain their food; the feet 
form a prehensile net of the most efficient nature, and the only 
currents produced result from its action. 
In habit, too, this animal differs from all known Cirripedes ; 
none I believe but this species bury themselves in hard calca- 
reous bodies: some indeed partially conceal themselves in foreign 
substances, and all may be said in a certain sense to be parasi- 
tical. Tubicinella and Coronula are well known to sink deep mto 
the skin of whales ; but in both cases the whole of the valvular 
or upper portion of the animal is exposed; and as both are well 
protected by their shells, it is evident that this habit is not for 
defence, the object apparently bemg to avoid that resistance of 
the surrounding element occasioned by the rapid movements of 
this huge animal, and the consequent difficulty there would be 
of maintaining thew hold of its smooth, contractile surface. 
Other genera, Prygona, Crusia and Acasta, are found concealed 
in corals and sponges; none of them however excavate: these 
bodies simply grow round the Cirripede, and as it augments in 
size, which it does by increasing upwards, so does the coral or 
sponge advance with it. Lithotrya is the only genus of the class 
that has been described as actually excavating a habitation m 
hard calcareous bodies; there is reason however to doubt the 
fact, as we shall see by carefully examining Mr. Sowerby’s own 
figures in his ‘ Genera of Shells.’ This creature is a pedunculate 
Cirripede, and is stated to have at “the base of the peduncle a 
shelly appendage.” For the moment granting this to be true, 
it is evident that the holes it occupies, if made by itself, can only 
have been formed by either this appendage, or by the base of the 
pedicle before the shelly appendage was secreted. But on refer- 
ring to the figures just alluded to, it would appear that neither 
hypothesis is correct. In one of these figures there is very cor- 
rectly delineated a couple of Serpule adhering to the under sur- 
face of the basal appendage. Now it is pretty clear, that were 
this appendage used as a rasping surface, no Serpule could exist 
as represented ; and were the excavations effected before the for- 
mation of this appendage, it must necessarily partake of the 
shape of the base of the newly-formed chamber to which it would 
be closely adherent, as in the parallel case of Hipponyz : it would 
