IsTO TE. 



At the suggestion of Mr. J. F. "Whitcavo^, Palffioritologist and Zoologist 

 to the Geological Survey, his Assistant, Mr. A. II. Foord, has undertaken 

 the study of certain Cambro-Siluiian fossils that require microscopic 

 examination to determine their generic and specific affinities. 



In pursuance of this suggestion the throe following papers, one on the 

 MonticuliporidiD, the second on some Polj'zoa from the Trenton Formation 

 and the third on the genus Tetradium, have been prepared, and are 

 herewith submitted. 



It must be understood that the author is alone responsible for the 

 correctness of the views expressed. 



ALFRED Pt. C. SELWYN, 



Dircclor Geological and Natural History Survey. 



Ottawa, May, 1883. 



