94 
duced in a perpendicular direction ; the termination, containing the 
aperture, which is round, standing upwards. It is from the neigh- 
bourhood of Verona. 
Plate VII. Fig. 4, is a small serpulite, the turns of which are 
spirally disposed on a horizontal plane, excepting the last ; which, as 
in the preceding fossil, turns upwards. 
The Kentish chalk fossil, Plate VII. Fig. 11, is a serpulite of a very 
curious form and character. It is formed of four spiral turns, the last 
of which is carried out a little way in a straight line, and then appears to 
have had its termination marginated. From its aperture another tubular 
body appears to have proceeded, the inferior part of which closely 
imitates, in its general appearance, the fringed, rugous, flat disc, serving 
as the foot of the snail. This also terminates with a marginated ring, 
forming a round aperture. The whole surface of the shell is marked 
bv very fine transverse strise ; and at distances, inci easing as the shell 
has grown, distinct annular projections are observable. 
The extraordinary form of this shell, and particularly the appear- 
ance of that part, which, though it must, always have been of a shelly 
hardness, bears so close a resemblance to the soft rugous part of the 
snail, led me very anxiously to seek for opportunities of examining its 
internal structure. I at last obtained two other specimens ; and then 
found, on carefully breaking them, that at each of these annular 
projections, and at that part where the shell seems to commence 
anew, a close internal septum existed, which presented externally a 
concave surface, and which prohibited any communication of the 
chambers with each other, or with the animal, which doubtlessly 
lived only in the last formed chamber. 
In this fossil we first observe a peculiarity of formation, which, as far 
as my knowledge extends, has not yet, although known to exist in 
several instances, obtained that attention which it seems to demand. 
In the nautilus, it is generally believed, that the division ol the shell 
into chambers, into each of which a part of the animal is extended, 
