80 CRUSTACEA—CIRRIPEDIA CHAP. 
Society’s Z’ransactions, Sir Robert Moray describes what he takes 
to be little birds enclosed in Barnacle shells, washed ashore on 
the coast of Scotland: “The little Bill like that of a Goose, the 
Eyes marked, the Head, Neck, Breast, Wings, Tail, and Feet 
formed, the Feathers everywhere perfectly shaped and blackish 
coloured, and the Feet like those of other Water-fowl, to my 
best remembrance.” Cuvier in his classification of the animal 
kingdom included them in the Mollusca; and it was not until 
1830 that J. V. Thompson described their larval stages, and 
showed conclusively that they belonged to the Crustacea. Since 
the work of this naturalist a number of observers have securely 
founded our knowledge of the group, but we may especially 
mention the epoch-making works of Darwin,’ Hoek, and latterly 
of Gruvel.® 
The young Cirripede is hatched out from the maternal 
mantle-cavity as a free-swimming Nauplius, a larval form 
common to most of the Entomostraca and to some Malacostraca ; 
the Cirripede Nauplius (Fig. 49) is characterised by the presence 
of well-developed frontal horns, and usually by the long spiny 
processes which spring from various parts of the body. As 
an introduction to the study of the group, it will be well to 
follow the transformations of this larva in ZLepas up to the 
period when it begins its sessile existence. The liberated 
Nauplii swim freely near the surface of the sea, and remaining 
in this condition for several days are dispersed widely from their 
birthplace ; they are then transformed by the process of moulting 
into the second larval stage, known as the Cypris (Fig. 50), 
from its resemblance to a bivalve Ostracod. The Cypris larva 
continues to swim about by means of the six pairs of biramous 
thoracic legs until it finds a suitable place on which to fix; 
in the case of Zepas fixation usually takes place on loose floating 
logs; the Cypris fixes itself by means of the first antennae, at 
the bases of which a large cement-gland secretes an adhesive 
substance. The biramous swimming legs are cast off, and 
six pairs of biramous cirri characteristic of the adult take their 
logical origin to the legend, the Barnacle goose (deriv. Hibernicula, bernicula=Trish 
goose) being confounded with pernacula, bernacula, a little shell. 
1 « 4 Monograph of the Cirripedia,” vols. i. and ii., Ray Society, 1851, 1853. 
2 «*Rep. on the Cirripedia, H.M.S. ‘Challenger,’” vols. viii. and x., 1883. 
$ “‘Monographie des Cirrhipédes,” Paris, 1905, in which will be found full 
references to literature. 
