152 BRITISH DESM1DIAOE.E. 



Length 375 /x ; breadth 58 /x. 

 ENGLAND. Sheep's Green, Cambridge ! 



Var. coloratum Klebs. (PI. XVIII, fig. 10.) 



Gl. Lun\il b. coloratum Klebs, Dosm. Ostpreuss. 1879, p. 6,t. 1, f. 1 a,d,c; 



De Toni, Syll. Alg. 1889, p. 832. 

 Cl. coloratum (Klebs) (lutw. Nonn. Alg. Nov. 1896, p. 38, t. 6, f. 1(3. 



Cell- wall of a reddish-brown colour. 

 Length 633-640 ^ ; breadth 90-102 p. 

 ENGLAND. New Forest, Hants ! 

 Geuyr. Distribution. Austria. Paraguay. 



r riiere is no just reason for regarding this form as a species 

 distinct from Cl. Lunula. The only distinction is the colour 

 of the cell- wall. 



Var. biconvexum Schmidle. (PI. XVIII, fig. 11.) 



Cl. Lunula var. biconvexum Schmidle, Beitr. alp. Alg. 1895, p. 10 (sep.), 

 t. 14, f. 18. 



Cells about 5 times longer than their diameter, outer 

 margin 50-55 of arc, inner margin convex (about 30 

 of arc) ; cell-wall colourless. 



Length 530-603 /u; breadth 11 0-1 26 /A. 



ENGLAND. Bowness, Westmoreland ! 



<i<'oyr. Distribution. Austrian Tyrol. Caucasus. 



Var. intermedium Gutw. (PL XVIII, fig. 12.) 



Cl. Lunula var. intermedium Uutw. Nonn. Alg. Nov. 1896, p. 39, t. 6, f. 17 ; 

 West & G. S. West, Alga-fl. Yorks. 1900, p. 52. 



Cells 5-6^ times longer than their diameter, outer 

 margin more convex (about 70 of arc), inner margin 

 prominently inflated in the median portion (sometimes 

 entirely convex), apices somewhat suddenly attenuated 

 and truncate. 



Length 408-660 ^ ; breadth 71-140 p. 



ENGLAND. Near Bowness, Westmoreland ! Bog two 

 miles S. of Clapham, W. Yorks ! 



. Distribution. Galicia in Austria. 



