INHABITING MULTILOCULAR SHELLS. 43 
been already given by Cuvier to a genus of Annelides, could not be 
retained ; and on the discovery of new species among some fossils from 
Cornwall the name Endosiphonite was proposed, as indicating the 
chief peculiarity in the genus, and also having analogy with the names 
of other fossil genera of multilocular shells.* The number of spe- 
cies already determined amounts to sixteen or seventeen, thirteen of 
them German. They are all probably referrible to the same geolo- 
gical period, which is one of the very earliest in which fossil remains 
are found. 
The Spirula is a shell well known to conchologists by a recent 
species, and apparently very common in many parts of the ocean, but 
unfortunately the history of the animal whose habitation it is we are 
not yet able to give ; for, although the shell abounds in many places, 
the animal is never attached, and there is even some degree of doubt 
as to whether it includes the shell or is included by it. In all proba- 
bility the former is the case. 
In the transition limestone of (Eland, an island on the south-east- 
ern coast of Sweden, there is found a fossil which has been called 
Lituite, but which seems, as far as can be told, to belong to this ge- 
nus Spirula. Both are spiral shells, with the whorls of the spine not 
close to each other, as in Nautilus; and both have simple septa, and 
a siphuncle nearer the inner than the outer margin. As these Litu- 
ites seem confined to the transition limestone, and the Spirula has 
never been met with in a fossil state, it will be a very singular ano- 
maly in natural history if these eventually prove to be referrible to 
the same genus ; for there is no known instance of a genus being re- 
created after it has been once extinct. 
If we conceive the shell of a Spirula straightened out, so as to pre- 
sent the appearance of a series of cup-like chambers placed over one 
another nearly vertically, we shall have the Orthoceratite, a genus so 
named from its resemblance toa straight horn. It is entirely con- 
fined to a few very ancient formations, although the number of ascer- 
tained species is more than fifty, and the abundance of individuals 
perfectly incredible. The size, too, which some species reached was 
extremely large ; for they have been found more than three feet in 
length, and with a diameter of more than six inches at the opening. 
* The description of this genus from the English species will be found in 
the forthcoming volume of the Cambridge Philosophical Transactions, where 
also the analogies with allied genera are more fully discussed. Count Miin- 
ster’s paper is translated in the Annales des Sciences Naturelles, 1834. 
