130 BRITISH DESMIDIACE^:. 



Cells of medium size, about as long as broad, including 

 the processes, but sometimes either slightly longer or 

 shorter than broad ; deeply constricted, sinus acute, 

 opening widely, with a minute excavation at its apex : 

 semicells subelliptical or subcuneate, apex and lateral 

 margins slightly convex ; angles prolonged to form 

 short stout horizontal processes, which are truncate at 

 their apices, tipped with a circle of minute granules, 

 and with several concentric series of granules 

 beneath ; upper part of faces of semicell with several 

 longitudinal series of granules, the uppermost granule 

 of each series being developed into an emarginate 

 verruca ; base of semicell with a circle of simple 

 granules. Vertical view triangular, sometimes quad- 

 rangular ; sides concave, with a series of emarginate 

 verrucse just within the margin ; angles slightly pro- 

 duced into short truncate processes ; centre of apex 

 smooth. 



Zygospore unknown. 



Length 35-45 (JL ; breadth 30-53 ji ; breadth of isth- 

 mus 10-11 '5 u. 



ENGLAND. Loughrigg, Westmoreland ! Cam Fell,. 

 W. Yorks ! Bog near Widdale Beck, N. Yorks ! Epping 

 Forest, Essex ! New Forest, Hants (Bennett}. Near 

 Chapel Wood, Surrey ! Dartmoor, Devon (Harris). 

 Near St. Just, Cornwall ! 



WALES.- -Llyn Ogwen, Carnarvonshire ! 



SCOTLAND.- -Ross, Inverness, Aberdeen, Kincardine, 

 Forfar, C41en Logie!, Perth, Fife, and Arran(/?o?/ & Biss.). 

 Orkneys ! Shetlands ! 



IRELAND. --Dublin and Wicklow (Arch.). 



Geogr. Distribution.-- France. Austria (var.). Norway. 

 Sweden. Finland. Denmark. Bornholm. Spitzbergen. 

 Greenland. Siberia (var.). Central China (var.). Java. 

 Central Africa. New Zealand (var.). Brazil (var.). 



There seems little doubt that St. Borgeanum Schmidle is 

 identical with. St. proboscidium (Breb.) Arch., although the 

 figures in Ralfs, 'Brit. Desm.' are not particularly good. The 

 British specimens are often not exactly typical, being charac- 



