CIRRHOPODES. 
385 
Our seas produce a small species {^Patella anomala, Mull.). 
The Discin<e, Lam., are Orbiculae whose inferior valve is notched with a fissure.* We must also approximate to 
the Orbiculae, 
The Crania, Brug-., whose animal has equally ciliated arms, but the shells have deep and round internal mus- 
cular impressions, in which some have fancied they saw a likeness to the figure of a skull. One {Anomia cranio- 
laris, Linn.) is a native of our seas. There are many fossil species, of which M. Hoeninghaus has given a beautiful 
monograph. 
[The Producta of Sowerby is a fossil genus, with a shell somewhat like a Cardium in figure, and rendered re- 
markable by the manner in which the anterior margin is produced beyond the part inhabited by the animal. The 
species are, to a certain extent, characteristic of the strata of secondary formation, and particularly of the carbon- 
iferous or mountain limestone.] 
THE SIXTH CLASS OF THE MOLLUSCA. 
THE CIRRHOPODESt (Lepas and Triton, Linn.) 
In several points of view the Cirrhopodes effect a sort of connection between this sub- 
kingdom and that of Articulated Animals. Enveloped in a cloak, and in a shell whose valves 
often resemble those of several of the Acephales, their mouth is furnished with lateral jaws, 
and the abdomen with filaments named cirri, arranged in pairs, composed of a number of little 
ciliated articulations, and representing a kind of feet or swimmers, such as we see under the 
tail of many Crustacea. The heart is situated in the dorsal region, and the branchiae on the 
sides : the nervous system forms a series of ganglions in the abdomen. However, it may be 
said that the cirrhous feet are merely the analogues of the articulated appendages of certain 
Teredines, while the ganglions are in some respects only repetitions of the posterior ganglion 
of the Bivalves. The position of these animals in the shell is such that the mouth is at the 
bottom, and the cirri near the orifice. Between the two last cirri there is a long fleshy tube, 
which has been sometimes inadvertently mistaken for a proboscis ; and at its base, near the 
back, is the vent. The stomach is puckered with a number of little cavities in its parietes, 
which appear to fulfil tlie functions of a liver : 
we notice besides a simple intestine, a double 
ovary, and a double serpentine canal termi- 
nating in the extremity of the fleshy tube pre- 
viously mentioned. The eggs pass through this tube, 
and in their course are exposed to the influence of 
the seminal fluid. The Cirrhopodes are all fixed. 
Linnaeus considered them all as belonging to one 
genus, which Bruguikes divided into two, and 
these have recently been much subdivided. 
The Anatifa, Brug. — 
Has a compressed cloak, open on one side, and sus- 
pended to a fleshy tube, varying greatly as to the 
number of testaceous pieces with which it is furnished. 
The animal has twelve pairs of cirri, six on each side ; 
those nearest the mouth are the shortest and thickest. 
The branchiae are elongated pyramidical appendages, 
that adhere to the external base of the whole of the 
cirri, or of part of them. 
In the commonest species (Pentalasmis, Leach) the two 
principal valves have a considerable resemblance to those of 
Fig. 194 .— Group of Anatifa, attached to a ship’s bottom. a Mussel ; two Others serve to complete a part of the margin 
of the shell opposite the beak ; and a fifth odd one unites the 
• [“We have shown that Lamarck’s new genus Discina ought to be | Orbicula norvegica, which we sent to him.” — SowerbyA 
entirely expunged, as being actually formed from some specimens of | 4 The Cirripedes of Lamarck : the Nematopodes of Blainville. 
c c 
