35 



With the hope of facilitating the distinction and ar- 

 rangement of those sponges which may be discovered in a 

 mineralized state, it has been thought advisable to give the 

 following table of the divisions of sponges which have been 

 adopted, and of the species which have been noticed, by 

 M. Lamourouxf ; adding those specific characters which 

 appear to be most distinctive and most likely to be dis- 

 coverable in the fossil specimens. 



I. Sessile masses, simple or lobated, either covering or 

 enveloping. 



1. S. communis Large flattish masses, rather 



convex ; pores large ; crevices 

 and grooves chiefly beneath. 



2. lacittulosa Surface finely porous, downy 



and jagged ; edges ciliated. 



3. sinuosa Tissue fibrous and stiff; holes and 



crevices numerous and deep. 



ductions of this class. Sponge being however considered to belong 

 to the animal world, forms an apparent objection to this conclusion. 

 But it must be remembered that Linnaeus was inclined to regard 

 sponge as a vegetable substance, and to place it in the class crypto - 

 gamia, subdivision algae aquaticae ; but was doubtful of the cor- 

 rectness of this arrangement. "May not the fact," Dr. Fyfe 

 observes, " that sponge contains iodine, be an argument in favour 

 of the opinion of Linnaeus, that this substance properly belongs to 

 the vegetable world, class cryptogamia, from the plants of which 

 iodine is obtained ?" Account of some Experiments, made with the 

 view of ascertaining the different Substances from which Iodine can 

 be procured. By Andrew Fyfe, M. D. The Edinburgh Philoso- 

 phical Journal, vol. 1, p. 254. 



t Histoire des Poly piers Coralligenes flexibles, &c. par J. V. F. 

 Lamouroux, D. E. S. Caen, 1816. 



