376 



Dr. J. J. Bigsby's Brief Account of the [Feb. 21, 



Himalayas, Russia, North and South America, and many other regions 

 offer ample fossil evidence of the general presence of the constituents of 

 this period. 



Table B. 



Kingdom or Order. 



Plantse 



Amorphozoa 



roraminifera 



Annelida 



Hetero-Pteropoda 



Bryozoa 



Zoopliyta 



Crinodea "l 



Cystidea > 



Asteriada J 



Trilobitffi 



Entomostraca 



Brachiopoda 



Monomyaria 



Dimyaria 



Gasteropoda , 



Cephalopoda 



Pisces 



No. of 



Species. 



74 

 120 



25 

 132 

 239 

 383 

 432 



456 



1414 

 242 



1372 

 123 

 439 

 715 

 955 

 34 



7155 



America 



and 

 Europe. 



2 

 9 

 9 

 15 



179 



America, 

 Europe, and 

 Australia, 



2? 



5? 



America 



and 

 Australia. 



Europe 



and 

 Australia. 



Total. 



4 

 16 

 20 

 18 

 7 

 1 

 1 

 23 

 1 

 64 

 2 

 9 

 9 

 15 



195 



The Silurian beds, it must be borne in mind, are usually visible in mere 

 shreds and remainders, met with in any one place only as a stage or a 

 part of a stage, the other portion being covered for perhaps thousands of 

 square miles by more recent deposits, or removed by denudation ; or it may 

 be that certain stages have never existed, as we see in Arctic xlmerica 

 with respect to the Lower Stage ; while in the South, as in Sardinia, 

 France, and Spain, it is the Upper Stage that is wanting, or very nearly so. 



But the visible geographical spread of these strata is often very great. 

 So extensive are the Silurian areas of North America (2000 miles across) 

 that it only needs a short and easy step to induce a belief in a former uni- 

 versal prevalence and domination of this system. 



Sufficient territory resting on Silurian rocks has been spared from 

 oscillatory action to enable us to trace it in one or other of its parts over 

 a large part of the earth. "We follow it circuitously from England to 

 Australia, or to America — the interspaces being filled up either by sea, by 

 newer rocks, or by kindred paleeozoic strata, which themselves irresistibly 

 bespeak its frequent continuous existence near at hand. 



This is only a fragment of the argument 'in favour of the doctrine of 

 Universality of epochs, as just defined. 



Localit2j. 



The ' Thesaurus ' brings conspicuously into view the great influence of 



