264 SUPPLEMENT 
that which is not by one or many partitions, which divide it 
into several cavities named chambers, concamerations, lodges, 
or cells. 
The shells which have but a single cavity are called wni- 
locular or monothalamous, as is the case with by far the 
greater portion of the univalves. 
Those which, on the contrary, have their cavity separated 
into a great number of lodges are named, in opposition, mul- 
tilocular, polythalamous, chambered, celled, &c. 
The form of the partitions, which may be very different, has 
determined the names of partitions. 
Even when they are simple. 
Sinuous when they present, and especially on their edges 
at the point of junction with the shell, certain sinuosities or 
sections, which have been compared to those on the edges of 
a leaf of parsley ; from the same cause they are also named 
by French conchologists decoupées, persillées, words for which 
our less flexible language furnishes no equivalent. 
It is from this disposition that in fossil conchology have 
been formed the names of articulated shells, of articulation 
derived from the disposition which the pieces of foreign sub- 
stance which have been moulded into these anfractuous 
cavities, preserve among themselves, and which are observed, 
after the shell itself has been destroyed. These articulations 
may be compressed, cylindrical, ventruous, &c. 
These different chambers, or particular lodges, communi- 
cate more or less completely between themselves by means of 
a hole in the form of a canal, which traverses the partitions. 
This hole is named siphon, and has been studied, 1. accord- 
ing to the number, which is never above two, as in tae oisy- 
phytes, but in most cases there is but one; 2. as to position, 
it may either be in the middle of the partition or approached 
to one of its extremities, from whence the names of 
Medial, when it is at the middle. 
