COSMAEIUM. 55 



broad, deeply constricted, sinus very narrow with a 

 dilated apex; semicells subhexagonal-reniform, basal 

 angles subrectangular and rounded, sides parallel (in 

 the lower part), upper angles broadly and obliquely 

 rounded-truncate, apex truncate and straight. Side 

 view of semicell obovate-circular. Vertical view sub- 

 elliptic, ratio of axes about 1 : 1*4. Cell- wall finely 

 punctate. 



Zygospore unknown. 



Length 37-47,/-t; breadth 30-30 /u ; breadth of 

 isthmus 9-12 /LI ; thickness 18-24 /i. 



EXGLAXJ*.- -Blea Tarn, Westmoreland ! Hawkshead. 

 Lancashire ! Mickle Fell and Pilmoor, X. Yorks ! 

 Skip with Common, E. Yorks ! Chobham Common, 

 Esher Common, and Devil's Jumps, Surrey ! 



WALES.- -Capel Curig and Llyn-y-cwm-ffyiion. 

 Carnarvonshire ! 



SCOTLAND.- -Loch Liver, Sutherland ; near Tain. 

 Eoss ; Loch But liven, Inverness ; Slewdrum, Acli- 

 verran, and G-leii Callater, Aberdeen ; Cammie, Bishops' 

 Dam, and Clochnaben, Kincardine; Mull, Argyll (L'<i 

 $'Bis*ett). Ehiconich, Sutherland ! Glen Shee, Perth ! 

 Lewis, Harris, and X. Uist, Outer Hebrides ! 



ICELAND. Mavo ! Galwav ! Kerry ! Donegal ! 



e/ t/ v 



Dublin and Wicklow (Archer). 



Geogr. Distribution.- -Germany. Austria and Galicia. 

 Norway. Sweden. Bornholm. Poland. Greenland. 

 Siberia. Japan. Central Africa (var.). United 

 States. AY. Indies (form). 



This is a well-marked species easily distinguished by tin* 

 rectangular basal angles and the obliquely truncate upper 

 angles of the semicells. Gutwinski gives the following range 

 of measurements for Austrian specimens: Length 27*6-51 /< ; 

 breadth 25'3-44/Li ; breadth of isthmus 6'9-14 /i. 



Var. cambrense (Turn.) West & G. S. West. (PL 



LXX, fig. 3.) 



0. gotlfiinlicvm Wittr. var. cambrense Turn. Desm. Notes, 1893, p. 3 

 (p. 344). 



