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TRANSACTIONS OF THE 



ture is revealed ; it may be described, by saying that 

 the cylinder is made up of convex layers of sandstone, 

 piled upon one another." From the known fleshy 

 organization of the aquatic cryptogamse, it is difficult 

 to conceive, how mere petrifaction, to say nothing of 

 " weathering" could produce a structure similar to that 

 noticed in the stems above alluded to. 



Two years subsequently to the publication of the F. 

 Brongniartii, Mr. Mantell described and figured a 

 Fucus, by the same name, though of a very distinct spe- 

 cies, ( Vide u Geology of the south east of England," 

 p. 95,) where this author states — "A fine species of 

 Fucus has been noticed in chalk, which I have named 

 in honor of the distinguished author of the Vegetaux 

 Fossiles, Fucoides BrongniartiiP We leave it to fu- 

 ture systematic writers to correct these trivial collisions 

 in classification. We learn from Professor Brongniart 

 that it is his intention to favor the public with a com- 

 plete synopsis of fossil vegetables, at the termination of 

 his great work. 



F. Alleghaniensis, Harlan. 



Journal of the Academy of Natural Sciences of Philadelphia, vol. vi. p. 289. 

 pi. xv.; R. C. Taylor, Louden's Magazine of Natural History, No. 37, for 

 January, 1834, p. 27, fig. vi. 



Locality. Eastern ridges of the Alleghany mountains. 

 Place in the Geological series. Compact sandstone, 

 subjacent to the coal measurers. 



(To be continued.) 



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