6 GEOLOGICAL AND NATURAL HISTORY SURVEY OV CANADA. 



Batostomella^ TJlricli. 



Leioclemay Ulrich. 



A(actopora, Ulrich. 



Callopora, Hall. 



Calloporella, Ulrich. 



Aspidopora, Ulrich. 



Ileterotrypa, Nicholson, (restricted). 



Dekayia^ Edwards and Hainic. 



Dekaydlay Ulrich. 



Fetigopora^ Ulrich. 



Nehulipora, (?) McCoy. 



Discoirypa, Ulrich. 



Spatiopora, Ulrich. 



StelUpora, Hall. 



Sub-genus ConsteUaria, Dana. 



Mr. T. 0. Weston, of this Survey, has skilfully prepared the numerous 

 microscopic sections required for the determination of the genera and 

 species. In the study of the various species a Ilartnack microscope was 

 used, and the magnified illustrations wore made by means of an Ober- 

 haouser camera lucida. It was found impossible to give satisfactory 

 magnified representations of the suriiice characters of the Monticuli- 

 porida), owing to their bad state of preservation. 



In conclusion the author desires to acknowledge his obligations to the 

 following gentlemen who have assisted him: Mr. E, O. Ulrich, of 

 Cincinnati, for valuable notes and critical remarks upon many of the 

 species described, Mr. R. Etheridge, jun., and to Dr. H. Alleyno 

 Nicholson, for friendly assistance and advice. Principal Dawson, of 

 Montreal, for the loan of a series of specimens from the Museum of McGill 

 College, and to Mr. Walter R. Billings for the opportunity of examining 

 a large number of specimens collected by him in the neighbourhood of 

 Ottawa City. 



Ottawa, May, 1883. ARTHUR H. FOORD. 



