belonging to a new Order of the Class Cirripedia. — 309 
bifid, and exhibit for some distance upwards the appearance of 
two channels (fig. 8). There can be little doubt that these or- 
gans are for branchial purposes. 
The chamber in which the animal is lodged is partially lined 
with calcareous matter secreted by the tenant ; this lining is very 
thin, and principally confined to the side walls of that part in 
which the anterior portion of the animal is lodged: here the 
lining gradually thickens as it approaches the margins of the slit, 
aud passes a little beyond them, particularly towards its poste- 
rior termination. On looking down upon the slit this shelly 
lining (fig. 2) is seen distinctly projecting imwards from the 
margins, and exhibiting two or three longitudinal ridges mark- 
ing periods of growth, narrowing the opening backwards as the 
increase of the animal requires the advancement of the aperture 
in front. Shelly granules, d, may also occasionally be seen filling 
up the curved posterior extremity of the slit. 
Notwithstanding the abundance of this animal I have not yet 
been able to investigate the internal anatomy, many specimens 
having necessarily been destroyed in making the external exami- 
nations, and others suffered in attempts to remove them from 
their abode. This important part of the description must there- 
fore for the present be left almost untouched. 
The cloak below is free for a considerable way backwards ; 
above, immediately behind the slit, it is united in front with the 
true body of the animal, and behind, where the broad disc-like 
expansion is covered with the horny plate, it blends with a 
thickish layer of parenchymatous matter. The stomach is long 
and narrow, and passing downwards and backwards from the 
mouth bends rather suddenly forwards, and gradually tapering 
is continued into the cylindrical, fleshy pedicle which supports 
the arms, near to which it probably terminates. No caudal pro- 
longation of this part was observed similar to that which is com- 
mon to all the other Cirripedes ; the generative organs are there- 
fore probably modified in this animal. 
Adhering to the parenchymatous matter beneath the horny 
plate the eggs are found spread out into a leaf-hke expansion 
co-extensive with this part of the animal; but whether or not 
this is really the ovarium could not be determined. It may be 
that the eggs have reached this position in some such way as 
they are supposed by certain writers to arrive in the pedicle of 
the pedunculate Barnacles. However, in this animal it is certain 
that the ova are never arranged in lamin at the base of the arms 
as in the other Cirripedes, but that they are hatched in the posi- 
tion in which they have just been described. Of this I have had 
ocular proof. 
In the early stages of development the eggs (Pl. IX. figs. 5 
