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a lens, appears to be a mass of fine fibres forming very small meshes, 
similar to the large ones of which the body is composed. The foot 
stalk, which spreads out and is a species of basement by which the 
fig is attached to the body on which it grows, does not seem to differ 
from the general substance in its conformation. Hence M. Guettard 
concludes the sea-fig to be merely a sponge, differing from other sponges 
only in form, and possessing like them the property of imbibing water 
and losing it by compression. 
On comparing the structure of the sea-figs with that of these fossils, 
M. Guettard points out differences which are undoubtedly very essen- 
tial. In the pedicles of the fossils, he observes that circular points 
may] be seen, which will be found to be continued into the spheri- 
cal part of these bodies ; so that by different transverse sections they 
may be traced, passing on like so many vessels, from the pedicle into 
the substance, and even on to the surface of the fossil : whereas, in 
the sea-fig, the fibres have no such regularity of disposition, nor are 
they thus continued like tubes from the pedicle, into the substance of 
the fig. 
M. Guettard next describes the other kind of fossil, which belongs to 
the class of fungites, and which, like the ficoid fossils just treated of, 
are open at their superior and wider part, and in general possess 
somewhat of a conical form : and from their varying in length, width, 
and size, frequently bear a resemblance to cups, glasses, funnels, 
cones, &c. whilst others are longer, cylindrical, and even fusiform. 
This variety of figure is frequently dependant on the circumstances of 
the fractures which they have suffered ; these fossils, like the former, 
being rarely found in a perfect state. M. Guettard appears to have 
been entirely foiled in the attempt to discover any recent zoophyte 
which might be considered as bearing any analogy with these fossils. 
He first was disposed to consider them as being similar to the spongia 
elegans of Clusius, or the spongia diira of Sloane, but this opinion he 
found reason to relinquish, and was then induced to believe that they 
