256 87. riLiCES. 



miglit be almost repeated here, excepting that all the 

 counties of the 1 first provinces must be considered 

 dubious and inadmissible until verified by botanists fully 

 prepared to distinguish between P. Dryopteris and P. 

 calcareum ; the localities recorded for the former of these 

 two ferns, in Somerset, "Wilts, Oxford, Essex, and Glou- 

 cester, some or all of them, very probably belonging to 

 the latter species. At the opposite extremity also the 

 range and area of P. Dryopteris are somewhat more re- 

 stricted than those of P. Phegopteris, the present species 

 not having been recorded from the province of the North 

 Isles, and not ascending so high on the mountains. 

 Found in Lincolnshire, according to the London Flora, 

 but without the citation of any personal authority for the 

 statement, and I know of no other record for that county. 

 If Lincolnshire be incorrect, the line of limit would be 

 carried upwards from Warwick into Derby and York, — 

 that is longitudinally rather than latitudinally. 



1377. POLYPODIUM CALCAREUM, Sm. 



Area 1 3 3 * 5 6 7 8 9 10 11 12. 



South limit in Somerset, Wilts, Oxford, ? 



North limit in Cumberland, Durham. 



Estimate of provinces 11. Estimate of counties 15. 



Latitude 51 — 55. Uncertain ty^je of distribution. 



Agrarian region. Inferagrarian — Superagrarian zones. 



Descends below 100 yards, in the Peninsula. 



Ascends to 300 yards, or upwards, in N. England. 



Range of mean annual temperature 49 — 45. 



Native. Rupestral. The stations on record for this 

 species are much confused with those for P. Dryopteris, 

 through misapplications or transfers of their names. 



