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tt 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 im- 

 bibing 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 dura of Sloane, but this opinion he 

 found reason to relinquish, and was then induced to believe that they 



