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bore a nearer resemblance, in their general characters, to'some species of 

 madrepores than to any of the sponges. In several of these fossils he 

 discovered an outer layer, which appeared to differ from the general 

 substance of the fossil ; and his opinion, he thought, derived support 

 from this circumstance, for, on examining the interior lamina of these 

 fossils, he conceived that it much resembled the hard smooth part 

 which forms the corresponding parts in madrepores, &c. Madrepores 

 and corals, he observes, are covered by a substance which has been 

 distinguished as their cortical part, and immediately beneath this, 

 there is a smooth substance of very close and compact texture, in 

 which there are no striae nor traces of any fibres. With this latter 

 substance, he thinks, the external layer of these fossils exactly agrees : 

 and he is confirmed in the supposition that it originally belonged to- 

 them, and was not derived from the matrix in which they lay, by 

 observing that, in one specimen, several little flat shells of oysters 

 were adhering to this surface. 



Nothing, he thinks, in the fossil kingdom approaches so near to 

 these fossils, as the single-starred corals of the Baltic, described by 

 Fougt, and treated of in the former part of the present volume. 

 The only difference, M. Guettard remarks, is that the corals de- 

 scribed by Fougt have strife which extend from the centre of the 

 coral to the edge, in such a manner as to form a star. This diffe- 

 rence is however sufficient to remove all idea of similarity between 

 the two bodies ; since, as we have already seen, the star constitutes 

 the genus Madrepora, to which those corals belong, whilst in the 

 fossil bodies now under consideration, there exist none of the cha- 

 racters which mark any of the species of zoophytes, which we have 

 hitherto examined. 



Many of these fossil bodies, it will be seen, differ so much from 

 any known recent zoophyte, that were it not that vast numbers of 

 these must be concealed from us, in the numerous recesses of the 

 ocean, they would be concluded to possess not the least resemblance 



