TABLE OF CONTENTS. 



Page. 



§1. Discovery of the fossil plants of the Dakota group 3 



2. Surface-distribution of the Dakota group 10 



3. Stratigraphical distribution of the Dakota group 13 



4. The Dakota group considered as a marine formation 25 



5. Distribution of the leaves in the composition of the Dakota group 28 



G. Generic characters of the flora of the Dakota group 31 



7. Disconnection of the flora of the Dakota group from antecedent types 35 



8. The flora of the Dakota group in relation to climate 38 



9. Description of species 42 



10. On the general characters and the relation of the flora of the Dakota group 116 



11. Conclusion 130 





