The Era of Invertebrates 



to the fact that the sea was comparatively shal- 

 low, and that there were no large masses of 

 land running north and south to limit the 

 range of animals. The testimony of land plants 

 as to temperature is lacking, for only the faint- 

 est traces even of supposed seaweeds have been 

 found, but the abundance and variety of animal 

 life suggests a mild climate. 



The Cambrian rocks of Newfoundland con- 

 tain many important fossils ; and these rocks 

 are of great importance, because they were de- 

 posited in an uninterrupted series, one layer 

 after another, so that their record is unbroken. 

 Eastern New Brunswick, too, has furnished 

 much information to the paleontologist, and 

 the fossils in the rocks of northern and eastern 

 New York have been studied long and care- 

 fully. 



Coming upward, the rocks above the Cam 

 brian represent the Lower Silurian or Ordo- 

 vician era, the first name being derived from 

 the Siliires, or ancient inhabitants of Shrop- 

 shire, while the latter comes from another 

 Welsh tribe, the Ordovici. The early faunas 



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