96 Observations Concerning Fossil Organic Remains. 
_ It was, when pursuing these investigations, and engaged in 
the study of the genera and species of organic remains, 
that, with his customary sagacity, he remarked, how widely 
those species differ which are the products of more ancient 
importance 
tion that many fossil species are limited to particular rocks, 
ile others, on the contrary, possess a wider distribution ; 
ese last appearing to have enjoyed an organization which 
enabled them to live during a variety of changes, which ex- 
terminated those found only in particular rocks.* | 
My profound veneration for the high merits of Werner has 
occasioned the foregoing remarks, and which, I trust, have 
been made with propriety. 
Geological question proposed by M. Brongniart. 
(Deserip. geolog. des environs de Paris, p. 92.) — ae? 
“When we have in two formations remote from each oth- 
er, a difference of structure, but the same organic remains - 
of geol 
certain the particular strata which were formed at these 
