. 179 



Length 21-5-25 p. ; breadth 26-5-30 /i; breadth of 

 isthmus 6'5-Svft; thickness 14 ^. 



ENGLAND.- -Xear Bowness, Westmoreland ! 



IRELAND. --Small lakes between Clifden and Round- 

 stone, Gal way ! 



This species comes near to C. quadrans Turn., but differs 

 in being less quadrate,, in its proportionately greater breadth, 

 in the more rounded upper angles of the semicells, and con- 

 sequently in the much shorter sides. The cell-wall also is 

 smooth. 



It should also be compared with C. subdepressum West & 

 G. S. West ('Some N. Amer. Desm/ 1896, p. 247, t. 15, f. 15), 

 from which it is distinguished by the angular form of its 

 semicells, by the stouter vertical view, and by the smooth 

 cell-wall. 



34. Cosmarium succisum West. 

 (PI. LXII, figs. 14-16.) 



Cosmarium succisum West, Alg. W. Ireland, 1892, p. 146, t. 20, f. 22, 23; 



Nordst. Index Desrn. 1896, p. 248 ; West & G. S. West, Alg. S. England, 



1897, p. 486 ; Alga-fl. Yorks. 1900, p. 91. 

 C. tinctum Ealfs var. succisum West & G. S. West, Alg. X. Ireland, 1902, 



p. 34. 



Cells minute, about as long as broad, moderately 

 constricted, sinus open, with a short, narrow ex- 

 tremity ; semicells trapeziform-elliptic, angles rounded, 

 sides slightly retuse, apex broadly truncate (or very 

 slightly concave). Side view of semicell circular. 

 Vertical view elliptic, very slightly subtumid at the 

 middle on each side. Cell- wall smooth and of a yellow 



t/ 



or reddish-brown colour. Chloroplasts axile with one 

 pyrenoid. 



Zygospore unknown. 



Length 1 0-12-5 /x,; breadth ll-12'o p,; breadth of 

 isthmus 3*75-5 //,; thickness 6 (JL. 



ENGLAND. Wigton Moor, W. Yorks ! Riccall and 

 Skipwith Commons, E. Yorks ! Puttenham Common, 

 Surrey ! 



WALES. Capel Curig, Carnarvonshire ! 



IRELAND.- -Near Glenties and Lough Anna, Donegal ! 

 Creggan and Derryclare Loughs, and Clifden, Galway ! 



