Canadian Fossil Bryozoa. 229 



plates of illustrations drawn on stone from nature and from 

 sections by Prof. E. 0. IJlrich himself. They are excellent 

 and give, as a rule, all the necessary views required where- 

 with to determine the generic as well as specific characters 

 described in the text or observed in related species described 

 elsewhere. 



It follows then from the above digest made of Prof. 

 Ulrich's work on the Lower Silurian Bryozoa of Minnesota 

 that thirty- three references to Canadian species are found 

 belonging to twenty-one generic forms. 



IT. 



In his previous elaborate work entitled : •' Palaeontology 

 op Illinois, Part II., Section VI., Pal^eozioc Bryozoa, by 

 E. O. Ulrich, pp. 283 to 688, the following is a list of species 

 of fossil bryozoa therein recorded from Canadian localities : 



1. Protocrisina exigua, Ulrich, Trenton, Montreal, Que. 

 ( = Gorgonia [f] perantiqna, Hall, 184*7.) 



2. Leioclema minutum, Eominger [?] Western Ontario. 

 (= Callopora minutissima, Nicholson, 1875.) Devonian. 



3. Batostomella Trentonensis, Nicholson, Trenton lime- 

 stone of Ontario. 



4 Botryllopora socialis, Nicholson, Hamilton formation, 

 Arkona, Ontario, Canada. 



5. Arthroclema pulchellum, Billings, Trenton of Canada. 



6. Helopora fragilis, Hall, Clinton formation, Hamilton, 

 Ont, Canada. (Fig. d, p. 643.) 



These make in all twenty-seven genera and thirty-nine 

 species from Canada. 



Ottawa, June 18th, 1894. 



