CANADIAN ORGANIC REMAINS. 



On the CYSTiDEiE of the Lower Silurian Rocks of Canada, By 

 E. Billings, F.a.S. 



SECTION I. 



GEOLOGICAL POSITION, STRUCTURE AND CLASSIFICATION. 



I. Introductory Observations . 



As several elaborate and beautifully illustrated memoirs upon the 

 structure and affinities of the Cystidese have appeared during the 

 last few years, it would be superfluous, on the present occasion, 

 to enter upon a re-examination of the subject, were this decade 

 designed to circulate only among scientific men, for whom it would 

 be sufficient to give nothing more than the most concise technical 

 descriptions of the species. But being intended also for the use 

 of the students of Canadian geology — whose number is rapidly 

 increasing throughout the Province — it appears necessary to com- 

 mence with a general summary of what has been ascertained up 

 to the present time concerning the zoological characters and distri- 

 bution in time and space of this somewhat extraordinary group of 

 extinct organisms. By this course it is hoped that, while the 

 foreign geologist will receive all the intimation he desires of what 

 we are doing, the growth of science in our own country will also 

 be promoted. 



The Cystidese were a race of small marine animals, which 

 flourished vigorously during the Silurian period, but totally disap- 

 peared before the commencement of the Carboniferous era. They 

 were closely allied to that interesting family, the lily encrinites, 

 or Crinoids, and, like them, entirely covered, as with a coat of mail, 

 by a dermal or external skeleton of thin calcareous plates, which 

 were sometimes richly ornamented with radiating ridges or striae. 

 Attached to the lower extremity of the body was a short flexible 

 stalk, usually called the column, that served to anchor the animal 



