302 Figures and Descriptions of Canadian Organic Remains, 



condition would altogether preclude the capture of any prey ex- 

 cept such as might float by chance within their reach. Animals 

 rooted to the ground like a plant would fare ill were they orga- 

 nized to support life by the predacious mode only. 



" The fossil remains of the Cystideae consist for the greater part 

 of mere fragments of the plates and columns ; but these, in cer- 

 tain localities, occur in such prodigious abundance, that they con- 

 stitute the principal portion of strata of rock several feet in thick- 

 ness. Of many of the species specimens of the bodies are 

 exceedingly rare, and when these are discovered they are usually 

 more or less crushed and distorted. While the fossil Corals, 

 Brachiopods and Gasteropods may be collected in hundreds, few 

 cabinets can boast of half-a-dozen good Cystideans, even in those 

 countries where whole formations of rock are composed of the 

 exuviae of the race. 



" With respect to their distribution in time, they have been dis- 

 covered in Bohemia, by M. Barrande, in beds which lie in the very 

 bottom of the oldest rocks containing traces of animal life ; and 

 therefore, according to the present state of our knowledge of the 

 primeval fauna, they were among the first living things that made 

 their appearance upon the surface of this planet. The Lower 

 Silurian formation, in the several countries where it has been most 

 studied, has at its base a great thickness of stratified rocks which 

 are altogether without fossils — at least none have been discovered 

 in them up to the present time. Then follows in conformable 

 succession a series in which organic remains do occur, but not in 

 any great abundance. This is the lower half of the fossiliferous 

 portion of the Lower Silurian. In Great Britain these strata are 

 the Lingula Flags of Sir Roderick Murchison ; in Bohemia the 

 Primordial Zone of Barrande ; and in Norway and Sweeden the 

 Alum Slates, or Regions A and B, of M. Angelin, the leading 

 palaeontologist of that country. In America they have not been 

 distinctly recognized, although it is doubtfully anticipated that the 

 Potsdam sandstone and the lowest sandstones of the western states 

 may be of the same age. It is more probable that some of the 

 ancient schists in the eastern states, where a large trilobite of the 

 genus Paradoxides has been found, are of the age of this " pri- 

 mordial zone of life." In whatever way this point may be decided 

 hereafter, it is only in Bohemia that Cystideae have been found so 

 low down in the geological series. Four species have there been 

 discovered, together with twenty-seven species of Trilobites, one 



