BARNACLES ; THEIR FACTS AND THEIR FICTIONS. 
393 
turn over one of the sides of our galley, and thus expose its 
crew and their freight. 
The hulk of the somewhat globular body, which nearly fills 
its boat-shaped receptacle — called technically the capitulum, 
and is invested by a loose membranous “ sack ” — is composed 
of a thorax^ which supports the cirri, and of a special enlarge- 
ment, the prosoma, which contains the stomach. The mouth, 
which will be found in front of the first pair of cirri, is armed 
with a paired series of organs of mastication — mandibles, 
maxillae, and their palps — collectively termed trophi, and leads 
into a short oesophagus, which, in turn, communicates with a 
capacious globular stomach. The food, consisting of minute 
crustaceans, is wafted towards the mouth by the cirri, and is 
there seized, but not triturated by the trophi. After the juices 
have been absorbed, the rejectamenta are let out at the anus, 
wrapped up in an epithelial case of the stomach. Darwin believes 
that Lepas can throw up food via the sesophagus. The stomach, 
which sometimes has a pair of blind sacs (cceca) appended, is 
covered with a dark glandular mass, possibly exercising the func- 
tion of a liver, which communicates by large openings with its 
interior. The interior, which is somewhat wide at its 
commencement, makes a sharp turn upon the stomach, and 
after running along the dorsal aspect (i,e. beneath the carina) 
of the animal, and decreasing gradually in calibre, ends by 
an oval opening in the very rudimentary abdomen. The cirri, 
of which, as just stated, there are six pairs, consist each of two 
long elegantly curling arms, rami, fringed with hairs, and 
supported on a common pedicle. At the bases of the first pair 
may be seen certain filamentary appendages, which have been 
supposed to act as gills ; but this is doubtful, as in many 
Cirripedes they are quite absent. Moreover, the mere surface 
of the body and of the sack ” seems to suffice for respiration. 
Coiled up between the last pair of cirri, but much longer than 
the longest of any of these appendages, lies a whip-like organ, 
the penis, at whose base the anus opens. 
All Girripedia, with some exceptions — viz. certain species of 
Ibla and Scalpellum — are hermaphrodite ; some species, how- 
ever, of the genera just cited have their masculine energies 
reinforced by parasitic males, which — from their not pairing with 
the opposite sex, but, mirahile diciu, with hermaphrodites — 
Darwin has termed “ complemental males.” * At fig. 10 one of 
these “ cavalieri serventi ” is shown in situ. The peduncle is 
* We look in vain,” says Darwin, ‘^for any, as yet known, analogous 
facts in the animal kingdom.” None of the Balanidce have these comple- 
mental males.” 
