TACONIC SYSTEM. 143 



Stated above. Varieties of these two often resemble each other; their connection, however, 

 furnishes means for distinguisliing ihcm ; besides fossils are not unfrequent in the latter, even 

 in the denuded strata, but more have been met with in the former. 



I have now stated what appears to be essential in discriminating correctly the hmestones 

 and slates of the systems of rocks which lie in such close proximity to each other. I beheve 

 them to exist in nature, and worthy of consideration. 



