This, bhe fourth and concluding part of the third volume of " Palseozoic 

 Eossils," published by this Survey, consists, as indicated^more fully on its 

 title page, of four papers. Three of these are descriptive of palseozoic 

 fossils from various localities in the Dominion, and are illustrated by 

 eight text figures and twenty plates. The fourth paper is a revised list 

 of the fossils of the Guelph formation of Ontario. These four papers are 

 supplemented by an Appendix, which consists of a list of errata in this 

 and in previous parts, with an index to the whole volume. 



For permission to reprint the two text figures of Steganohlaslus Ot- 

 tawaensis from the third part of the " Treatise on Zoology ", edited by 

 Dr. E. Ray Lankester, and for cliches of the original blocks, the Survey 

 is indebted to the courtesy of the publishers, Messrs. Adam and Charles 

 Black, of Soho Square, London, England. 



A. P. LOW. 



Geological Survey of Canada, 

 Ottawa, June 23rd, 1906. 



