CONTENTS. 



Introduction. 

 A. From the Cambro-Silurian Eocks. 



1. Aparchi tes mundulus, nov. Trenton, Lorette Falls, P. Q. - - - 



2. Tyrrellii, nov. Chazy, Black Island, Lake Winnipeg - 



3. Primitia Logani, Jones. Chazy and Trenton, Aylmer, P.Q., &c. - 



4. mundula, Jones, var. eflfossa, nov. Chazy ? Quebec City 



5. mundula, var. incisa, nov. Trenton, Lorette Falls, P.Q. 



6. Beyrichia clavigera, nov. Chazy, Aylmer, P.Q. 



7. clavigera, var. clavifracta, nov. Chazy, Aylmer, P.Q. 



8. quadrifida, nov. Trenton, Lorette Falls - - - - 



9. Isochilina Ottawa, Jones, var. intermedia, nov. Chazy, Ottawa, &c. - 



10. Whiteavesii, nov. Trenton, Lorette Falls - - - - 



11. Amii, nov. Trenton, Lorette Falls - - - - - 



12. labellosa, nov. Chazy, Aylmer, &c. - - - - 



13. Leperditia Balthica {His) var. primseva, nov. Chazy, Carleton Co., 



Ont. 



14. sp. (comp. L. Hisingeri), Chazy, Aylmer - - - 



15. obscura, nov. Trenton, Lorette Falls - - . - 



B. From the Silurian Eocks. 



1. Primitia mundula, Jones. Arisaig, N.S. ------ 



2. Beyrichia sequilatera, Jlall. Arisaig 



3. tuberculata (Kloeden). Arisaig 



4. tuberculata, var. pustulosa, Hall. Arisaig 



5. tuberculata, var. strictispiralis, nov. Arisaig - - 



6. tuberculata, var. Noetlingi, Renter. Arisaig 



7. Isochilina grandis, var. latimarginata, nov. Long Point, Lake 



Winnepegosis, and Saskatchewan River - - - - 



8. Leperditia Balthica {His), var. Guelphica, nov. Durham, Ontario - 



9. Hisingeri, Schmidt. Long Point, Lake Winnipegosis 



10. Hisingeri, var. fabulina, nov. Long Point ; and Grand 



Rapids, Saskatchewan River - . - - - 



11. Hisingeri, var. gibbera, nov. Long Point, Lake Winni- 



pegosis 



