446 baker's north YORKSHIRE. 
In the sandstone quarry Castle Howard Park (Spruce. 
1844). 
Sea shore at Whitby (Ibbotson). 
Fruiting- 10-12 mths. 
Var. B. pusillum (Hedw.). 
In the quarry at Castle Howard Park, growing inter- 
mixed with the normal form (Spruce.). 
3. D. homomallum (Hedw.). Hampe. 
[Trichostoinmn homomalhun B. et S.). 
B. Range 1-2. 
Broken sandy ground and banks in 5»ub-alpine districts, 
not rare. Sandstone quarry and in some of the Castle 
Howard Woods (Spruce.). 
Near Caldron Snout, Upper Teesdale (M.B.S.). 
High Cliff, Guisbro' (Barnes). 
Fruiting 9-1 1 mths. 
5. D. flexicaule. (Schleich.). Hampe. 
[Tridiostojiiiim flexicaule, B. et S.). 
Montane B. Range 1-3. 
Limestone rocks and stony ground, not uncommon. 
This species Mollia (Tortula) tortuosa, and Neckera 
crispa, are amongst mosses, what Scabiosa columbaria, 
Poterium sanguisorba, and Carlina vulgaris are amongst 
the flowering plants, species distributed through the 
dysgeogenous tracts, and often growing there plentifully, 
but otherwise rare. These three mosses furnish typical 
illustrations of what I have called the Xerophilous role of 
distribution (Baker). 
Common upon dry banks amongst the calcareous hills 
upon both sides of the Central Valley. It grows on the 
magnesian limestone in various places and ascends on the 
