62 



J. P. PUGH 



101. KINTYRE : Campbeltown, 1950, M. H. Cunningham, (B.M.). 



104. N. EBUDES : S.W. of Kil-Marie, Strathaird Peninsula, Skye, 1951, D. J. Griffiths, (B.M.); 



Armadale, Skye, 1903, W. C. Barton (B.M.); Quiraing, Skye, 1884, E. F. Linton, (B.M.). 



105. W. ROSS : Diabaig, 1936, A. /. Wilmott, (B.M.); Strome Ferry, 1884, E. F. Linton, (B.M., Ox 



Cam). 



106. E. ROSS : Isle of Cromarty, ISSl, (Ox). 



lOS. W. SUTH. : Ben Hope, 1833, W. R. McNah, (NMI); Lochinver, 1890, E. S. Marshall, (Cam); 

 Meivich, 1886, E. S. Marshall, (Cam). 



111. ORKNEY : E. Corrie, onN.W. faceof Hoy Hill, 1880, H. H.Johnston, (NMI) ; Hammers, Syradale, 

 Firth, 1883, H. H.Johnston, (Ox); Houton, 1952,/. T. Syme, (K.Wats) ; Ramsdale, Swanbister, 

 1873,/. T. Boswell-Syme, (B.M.Bosw); Swartages, Birsay, 1921, H. H. Johnston, (E); nr. 

 Wastdale Mill Farm, Firth, 1880, /. T. Boswell-Syme, (B.M.Bosw). 



H. 1. S. KERRY : nr. Cloonee Loughs, 1952, A. H. G. Alston, (B.M.). 



2. N. KERRY : Killarney, 1952, A. H. G. Alston, (B.M.). 



3. W. CORK : Inchigeelagh, 1952, A. H. G. Alston, (B.M.). 



4. MID CORK : E. of Macroom, 1952, A. H. G. A/ston, (B.M.). 



7. S. TIPP. : Newcastle, 1882, /. Britten & C. Nicholson, (B.M.). 



8. LIM. : Foynes, 1902, C. G. Brien, (NMI). 



9. CLARE : Glen at Ennistymon, 1865, Hh. Churchill, (K); Kilfenora Bog, 1947, /. G. Dony, (K). 

 12. WEXF. : nr. Mt. St. Benedict, 1952, A. H. G. Alston, (B.M.). 



15. S.E. GALW. : Slieve Aughty, Dalystown, 1945, J. Manton, (K). 



16. W. GALW. : Clifden, 1907, /. W. White, (Cam); banks of Glen Inagh, 1900, /. S. Gamble, (K); 



Kylemore, 1855. R. Barrington, (K.Moore). 



20. WICKLOW : Ballyarthur, 1894, R. Lloyd Praeger, (NMI) ; nr. Enniskerry, 1894, R. Lloyd Praeger, 

 (NMI); Templemichael, Arklow, 1882, W. Fawcett, (B.M.); nr. Up. Lough Bray, 1855. 

 R. Barrington, (K.Moore). 



22. WESTMEATH : Knock Drin, 1895, E. S. Gregory, (B.M.). 



27. W. MAYO : Ballycray Mts, 1855, R. Barrington, (K. Moore); Inishturk, 1906, R. Lloyd Praeger, 



(WNH, NMI). 



28. SLIGO : Lough Gill, 1855, R. Barrington, (K.Moore). 

 33. FERM. : Slieve Rushen, 1949, P. Taylor, (Tayl). 



35. N. DON. : Killybegs, 1855, R. Barrington, (K.Moore). 



36. TYRONE : Omagh, 1896, M. C. R., (NMI). 



38. DOWN : Sandy Warren, Newcastle, 1893, S. A. Stewart, (NK4I). 



40. DERRY : below Glenbourne Pass, on road to Maghera, 1930, M. M. Whiting, (K). 



Discussion 



Von Wolf (1936) produced the map (fig. 3) to show the northern Hmits of D. horrer'i 

 Newm. in Europe : 



The map (fig. 4) showing the detailed distribution of D. horreri in the British 

 Isles, is in agreement with von Wolf's. From this map it can be seen that this 

 species occurs rather irregularly throughout the British Isles and, like most native 

 ferns, is more abundant in the west than in the east, since the higher humidity in the 

 west offers a more favourable habitat for this group of plants. The vice-comital distribu- 

 tion also requires comment. D. horreri may well be absent from Cambridgeshire, since 

 there are so few woods in this county, but would be expected to occur fairly frequently 

 in Yorkshire, Northumberland and Durham. The alkalinity of the soil in East Anglia 

 may, in some measure, inhibit D. horreri, although there is a small, isolated fen in the 



