Silurian Fossils. 6 



Secondly, whether the position of the fossil remains of plants 

 in the earth's strata is such as to lead us to believe, that a 

 cryptogamic flora preceded one consisting of flowering plants, 

 and that the less perfect of the phanerogamic orders were 

 created before the more perfect, and that the most varied 

 and complex floras were last in historical succession. 



Our eff'orts to arrive at sound theoretical views on this 

 important question may accelerate the future progress of 

 discovery by directing the collectors of fossils to points 

 where we stand most in need of information, or by stimulat- 

 ing another class of investigators to dredge the bottoms of 

 lakes and seas, in order to teach us what are the laws now 

 governing the imbedding of the remains of living plants and 

 animals in newly-deposited sediment. 



Sir C. Lyell now inquires, in the following pages from his 

 Anniversary Address, whether, when the fossils of the animal 

 kingdom are arranged by the geologist in a chronological 

 series, they imply that beings of more highly developed struc- 

 ture and greater intelligence entered upon the earth at suc- 

 cessive periods, those of the simplest organization being the 

 first created, those more highly organized being the last. 



Silurian Fossils. 



It may be aflirmed, he says, that the knowledge acquired of 

 late years of the Silurian fauna reduces at once the theory of 

 successive development wdthin very narrow limits ; for we dis- 

 cover even in the lower Silurian, a full representation of the 

 Radiata, Mollusca, and Articulata proper to the sea ; and 

 regarding it as a marine fauna confined to those three classes, 

 it might almost seem to imply a more perfect development 

 than that which peoples the ocean of our own times. Thus 

 in the great division of Radiata, we find asteroid and helian- 

 thoid zoophytes, besides crinoid and cystidean echinoderms. 

 In the Mollusca, M. Barrande enumerates, in Bohemia alone, 

 the astonishing number of 250 species of cephalopoda. In 

 the Articulata we have the crustaceans represented by more 

 than 200 species of trilobites, not to mention other genera. 



The remains of fish, hitherto referred to lower Silurian 

 rocks, have proved on closer investigation to be spurious, 



