INTJiODUCTION. 5 



in shatly woods, l)y waterliills and mountain streams, in hogs 

 or on peaty moors, growing on living and dead trees, on stone 

 walls and rocks or mud-covered walls ; some species are peculiar 

 to limestone, others to subalpine and alpine districts. Full par- 

 ticulars are given with each species, and if the student has any 

 doubt as to the determination of any species its habitat will often 

 afibrd a good clue to its correct name. 



Census of Distribution. — I have followed the admirable 

 arrangement adopted in the "London Catalogue of British 

 Mosses and Hepaticoe," 18S1. 



"The numbers 1 to IG and the lettered numerals 17a, 17b, 

 18a, 18b, and 18c, stand for the twenty-one Watsonian provinces, 

 and show in which of those provinces each species is known to 

 grow. The names of these provinces, with the numbers standing 

 for them in the catalogue, and the counties included in each 

 province, are as follows : 



1. Feninmlar (Cornwall, Devon, Somerset). 



2. Channel (Wilts, Dorset, Wight, Hants, Sussex). 



3. Thames (Oxon, Bucks, Berks, Surrey, Middlesex, Herts, 

 Essex, Kent). 



4. Ouso (North'ton, Beds, Hunts, Cambridge, Norfolk, Sutlblk). 



5. Severn (Monmouth, Glo'ster, Hereford, Worcester, Warwick, 

 Salop, and Stafford). 



6. South Welsh (Glamorgan, Carmarthen, Brecon, liadnor, 

 Cardigan, and Pembroke). 



7. North Welsh (Montgom., Merioneth, Anglesea, Carnarvon, 

 Denbigh, Flint). 



8. Trent (Lincoln, Leicester, Notts, Derby). 



9. Mersey (Cheshire, Lancashire, sine Lake Lane). 



10. Hiunher (Yorkshire solus). 



11. Tj/ne (Durham, Northumberland). 



12. Lake (Lake Lane, Isle of Man, Westmorland, Cumberland). 



13. West Lowland (Dumfries, Wigton, Kirkcudbright, Lanark, 

 Ayr, Renfrew). 



14. Eaxt Lowland (Berwick, Boxburgh, Selkirk, Peebles, 

 Haddington, Edinburgh, Linlithgow). 



