310 



88. PTERIDIOIDES. 



forms of this latter, on the other side E. variegatum 

 shades off, through Wilsoni and Mackaii, almost to E. 

 hyemale. I am not suggesting that all these should be 

 united into one species ; hut that the intervening species 

 (one or more), between palustre and hyemale, is not 

 clearly understood by the technical diagnosis hitherto 

 attempted to be drawn. The highest stations for E. va- 

 riegatum are probably on the line of the Tees, but to 

 what altitude it ascends that river I do not know. (See 

 Phytol. ii. 553 and 576 ; also Pliytol. i. 337, and 309). 



Provinces. 



1. Peninsula. 



2. Channel. 



3. Thames. 



4. Ouse. 

 6. Severn. 

 6. S.Wales. 



7. N. Wales. 



8. Trent. 



9. Mersey. 



10. Humher. 



11. Tyne. 



12. Lakes. 



13. West Lowlands. 



14. E. Lowlands. 



15. E. Highlands. 



16. W. Highlands. 



17. N. Highlands. 



18. N. Isles. 



