XXXII.—AN ACCOUNT OF THE PORTUGUESE AND FRENCH 
OYSTERS CULTIVATED IN THE BAY OF ARCACHON. 
By J. RENAvUD.”* 
A—AN ACCOUNT OF THE PORTUGUESE AND FRENCH 
OYSTERS. 
The oyster (Ostrea edulis) isa mollusk belonging to the class of Lamel- 
libranchiates. To form an adequate idea of its admirable conformation, 
‘it is necessary to study it with the microscope. 
The oyster is widely distributed in nature, each marine province 
counting one or more species in its fauna. Usually grouped in places 
most favorable to their development, they form considerable aceumula- 
tions, known under the name of Banks. The immense consumption of 
this mollusk, principally in Europe and “America, may give some idea 
of its fecundity, for its abundance does not seem to diminish in spite 
of the large quantities taken from the sea. 
The oyster which we now call the Portuguese was known to, and 
esteemed by, the ancients; the citizens of Athens regarded it as a dainty, 
and used its shell to write their votes upon. Subsequently, among 
the Romans, we find Pliny congratulating one of his friends on being at 
Marseilles, where he could have fresh oysters. 
The shell of the oyster is especially recognized by its irregularity ; 
living attached to sub-marine bodies it takes the imprint of them, and 
individuals of the same species are infinitely modified in consequence of 
the numberless accidents of position which they assume on the bodies 
to which they are attached. It is, therefore, necessary to examine a 
large number of individuals in order to recognize a species and learn 
its distinctive characteristics. One characteristic of oysters is the 
inequality of their valves, the one which adheres to foreign bodies being 
always the larger. These valves have received the name of upper and 
lower, in consequence of the usual position of the oysters; the lower 
valve is the larger, the upper one is also called the operculum. Never- 
theless, in the study of this mollusk, I shall follow the rule laid down 
by zodlogists for the study of bivalve shells in general, that is to say, L 
will suppose the animal to be standing upright before me. In this posi- 
tion the large valve is on the left, the small one on the right, while the 
*Notice sur L’Huitre Portugaise et Frangaise cultivée dans la Baie d’Arcachon. 
Arcachon, Imprimerie E. Faure et V. Aumassanne, 1878. Quarto pamphlet, 33 pp. 
[1] 931 
