116 
MOLLUSCA. 
Others project in a conical or globular mass* * * § , 
Or expand into a disk comparable to that of a flower or of an 
Actinia f, or are elongated into cylindrical branches supported by 
slender pedicles, &c. | or, form parallel cylinders §. 
Recent observations even seem to show that the Eschars, hitherto 
placed among the Polypi, belong to this family of the Molluscalj. 
CLASS V. 
BRACHIOPODA % 
The Mollusca Brachiopoda, like the Acephala, have a bilobed 
mantle which is always open. Instead of feet they are provided with 
two fleshy arms furnished with numerous filaments, which they can 
protrude from, and draw into the shell. The mouth is betAveen the 
base of the arms. Neither their organs of generation, nor their ner- 
vous system are well known. 
All the Brachiopoda are invested with bibalve shells, fixed and 
immoveable. But three genera are known. 
Lingula, Brug . 
Two equal, flat, oblong valves, the summits of which are at the ex- 
tremity of one of the narrow sides, gaping at the other end, and 
attached between the two summits to a fleshy pedicle, which suspends 
them to the rocks ; the arms become spirally convoluted previously 
to entering the shell. It appears that the branchiae consist of small 
leaflets, disposed around the internal face of each lobe of the mantle. 
But a single species — Lingula anatina, Cuv., Ann. du Mus., 
I, vi, Seb., Ill, xvi, 4, is known. It inhabits the Indian Ocean, 
and has thin, horny and greenish valves**. 
* The Euccelium, Savig. ; the Distomi are arranged in the same manner. 
•f" The genus Diazona, Sav., consisting of a large and beautiful purple species 
discovered near I vice by M. Delaroche. 
I The genus Sigillina, Sav., whose cylindrical branches are frequently a foot long, 
and the animals, slender as threads, but three or four inches. 
§ The genus Synocium, Lam. 
II Messrs. Audouin and Milne Edwards on the one hand, and M. de Blainville on 
the ether, have lately verified this fact, which the observations of Spallanzani pre- 
viously seemed to announce. 
^ M. de Blainville has given to my Brachiopoda, the name of Palliobran- 
CHiATA, and makes an order of them in his class of the Acephalophora. 
** Linnaeus, who knew but one of the valves, called it Patella unguis. Solander 
and Chemnitz, who were aware of its having two, ealled it, one, the Mytilus lingua, 
and the other. Pinna unguis. Brugi&res knew its pedicle, and consequently made 
a genus of it by the name of Lingula, Encyc. Method., Vers, pi. 250. It is 
singular that before us, no one had remarked that it is well figured with its 
pedicle by Seba, loc. cit. 
