STAURASTKUM. 123 



wider at the apex than at the base, basal angles 

 slightly rounded, sides faintly retnse, apical angles a 

 little dilated and rounded, apex strongly convex and 

 often flattened in the middle. Vertical view 3- 

 (5-gonal (commonly tetragonal or pentagonal), angles 

 rounded, sides almost straight. Cell- wall evenly 

 granulate all over ; granules for the most part without 

 any definite arrangement, but with distinct indications 

 of ring-like series around the angles. 



Zygospore unknown. 



Length 36-46 ^ ; breadth of base of semicells 

 17-20 jit, of apex 20-26 ^ ; breadth of isthmus 

 13-18 p.. 



ENGLAND.- -Bnttermere, and Blea Tarn in Borrow- 

 dale, Cumberland ! Ambleside and Blea Tarn 

 (Bissett), and Helvellyn !, Westmoreland. Xear 

 Cockley Beck, Lancashire! Blubberhouses (Turner'), 

 Baildon !, Ingleton!, Penygheiit !, and Cowoiil Wold 

 Moss on Widdale Fell!, W. Yorks. Mickle Fell, 

 N. Yorks ! Hartlebury Common, Worcestershire ! 

 Tintagel, Cornwall ! 



WALES. Grlyder Fawr, Snowdon, and near Llyn 

 Padarn, Carnarvonshire ! 



SCOTLAND. --General, but scarce! (Roy $ Bissett). 

 Skye ! Lewis, Outer Hebrides ! Orkneys ! Shet- 

 land s ! 



IRELAND.- -Xear Glen ties and near Lough Mag-rath, 

 Donegal ! Lough Derryclare, Gal way ! Carrantuo- 

 hill, and 8 miles S. of Kenmare, Kerry ! Dublin and 

 Wicklow (Archer). Westmeath (Archer). Slieve 

 Donard, Down (at 2000 feet) ! 



Geogr. Distribution.- -France. Germany. Switzer- 

 land. Austria and Galicia. Roumania. Italy. 

 Norway. Faeroes. Greenland. United States. 



ij 



St. Meriani is a very distinctive upland species. It occurs 

 in alpine and subalpine lakes, tarns,, and boggy rills; and 

 is also not uncommonly found amongst mosses and hepatics 

 on the dripping rocks of subalpine ghylls and glens. The 

 form of its semicells, combined with its uniform granulation, 



