390 
THE OCEAN WORLD. 
debted for our information respecting this curious mollusc, tells uS 
“ that the animal which inhabits this curious shell was first described 
by Russel, whose account of it is deficient in the anatomical details, 
which might explain the utility of the holes in the disk of the central 
fissure, and of the spiriform tubes found there.” We suppose that this 
arrangement is necessary in order to facilitate respiration ; and M. P e 
Blainville thinks the small tubes are intended for the passage of th® 
fillets which are necessary to fix the animal to the body on which h 
is to live, and in such a manner as to admit of its movements round a 
fixed point. 
The animal which inhabits the Aspergillum is elongated, contraC' 
tile, and only occupies the upper part of the tube, but it can stretch 
itself out sufficiently for all its wants. Shells of this genus are very 
rare, although a great number of species are known. They are f° uDt 
in the Red Sea, and in the seas of Australia and Java, The shell® 
are generally of a white or yellowish tint ; some have the tube cover 6 
with a glutinated sand, mixed with small fragments of shells of divei se 
colours. We know nothing of their habits, and their singular for 111 ® 
have left naturalists in doubt as to the place which should be assign 61 
to them in the method of arrangement. It is only after having 
recognised the existence of two valves, which was detected with g r ^ 
difficulty just under the disk, and forming part of the sheath in "dm ^ 
the animal is encased, that it has been decided to range them 
the Tubieola, and with the shells, presenting an arrangement analog 0 ’ 13 
or equally singular. These molluscs are, as M. Chenu says, h"" 
known, rare, and hence much sought for by collectors. They al ’ e 
exclusively exotic, the most common species being from Java. I* lS 
imported into Europe by the Dutch. 
