﻿ANNIVERSARY MEETING. — DONATION FUND. Xxhi 



and even more valuable from the perfect state of their preservation 

 than from their numbers. 



The 1 100 species may be divided into the different classes nearly as 



follows : — 



Crustaceans, chiefly Trilobites 250 species. 



Cephalopods 250 



Gasteropods and Pteropods 160 



Acephala 1 30 



Brachiopods 200 



Corals, &c. &c 110 



1100 



To a naturalist, it is not the least interesting circumstance attending 

 these discoveries, to learn that all these fossils were obtained from a 

 superficial area, not more extensive than one-sixtieth part of the 

 Adriatic ; and they certainly show that the Silurian Fauna was not 

 only as rich, but as much influenced by geographical conditions, or 

 as far from being uniform throughout the globe, as that of any sub- 

 sequent era. The preservation of the most delicate parts of many 

 species extending even to their embryonic states, enabled the author 

 to establish the fact of the metamorphosis of Trilobites in nineteen 

 Bohemian species belonging to ten different genera. It has been 

 shown that one species, called Sao hirsuta, presents itself under 

 twenty different forms, out of which preceding naturalists had made 

 eighteen species and ten genera, all now reduced to one species. It 

 is at length therefore distinctly ascertained, and for the first time, that 

 the development of the crustaceans followed the same laws in the 

 palaeozoic period as in our own times. 



To the geologist it is satisfactory to know, that the successive 

 groups of Bohemian fossils arranged stratigraphically, indicate a series 

 of changes in organic life corresponding in chronological order to those 

 of equivalent groups previously established for the classification of 

 the palseozoic strata of Europe and North America. It appears also 

 that the vertical range of certain species from the Lower to the Upper 

 Silurian division is very great, apparently in cases where there has 

 been a recurrence of similar geographical circumstances in the depth 

 and mineral deposits of the ancient sea. 



I need scarcely add, that no private individual of moderate fortune 



