304 88. PTERIDIOIDES. 



growth. Mr. Newman informs us, on faith of a specimen 

 gathered hy Dr. Young, that E. umhrosum grows in Mere 

 Clough, near Manchester ; hut I cannot certainly say 

 whether that clough is in Cheshii-e or Lancashire. The 

 other counties are York (Mr. G. S. Gibson !), Northumber- 

 land (Mr. John Storej^ !), "Westmoreland (Mr. James Back- 

 house), Lanark (Mr. H. M. Balfour !), Linlithgow (Prof. Bal- 

 foui' !), Fife or OchiUs (Dr. Dewar !), Stirling (Mr. Gourlie !), 

 Perth (Mr. H. M. BaKour !), Forfar (Mr. Thomas Drum- 

 mond), Aberdeen (Mr. H. M. Balfour!), and Inverness 

 (Prof. Graham). Will very likely be found in the "West 

 Highlands, and perhaps in the North Highlands also. 



1422. Equisetum arvense, Linn. 



Area general ? 



South limit in Cornwall, Isle of "Wight, Kent. 



North limit in Shetland, Orkney, Hebrides. 



Estimate of provinces 18. Estimate of counties 83. 



Latitude 50 — 61. British type of distribution. 



Agrarian region. Inferagrarian — Superagi'arian zones. 



Descends to the coast level, in the Peninsula. 



Ascends to 350 or 400 yards, in East Highlands. 



Range of mean annual temperature 52 — 43. 



Native. Inundatal, Agrestal, &c. Perhaps the least 

 affecting watery situations of any of the species of its 

 genus, yet commonly enough found in ditches and hollows 

 where water stands for weeks together in the winter sea- 

 son, and even for months during some wet winters. 



