COSMARiUM. 



Cooke, Brit. Desni. 1886, p. 96, t. 37, f . 14 rfi^ure bad] ; De Toni, Syll. 

 Alo-ar. 1889, p. 1045 ; Roy & Biss. Scott. Desm. 1894," p. 173 : Xordst. 

 Index Desm. 1896, p. 223 ; West & G-. S. West, Freshw. Chlorophy. 

 Koh Chang, 1901, p. 90. 

 Ursinella Reinschii Kuntze, Revis. gen. plant. 1891, p. 925. 



Cells rather small, about ly times longer than 



broad, very deeply constricted, sinus narrowly linear 



/ / / 



with a dilated apex ; semicells trimcate-pyramidate, 

 basal angles rounded, sides convex with about 4 acute 

 undulations (slightly increasing in size towards the 

 apex), apex slightly produced and broadly truncate, 

 upper angles not rounded or very slightly so. Side 

 view of semicell subcircular. Vertical view elliptic, 

 with a rounded inflation at the middle on each side, 

 ratio of axes about 1 : 17. Cell- wall minutely punc- 

 tate. 



Zygospore unknown. 



Length 36-37 /; breadth 27'5-30/u; breadth of 

 isthmus 7-8 ju; thickness 15-16 /u. 



Ex< rLAND.- -Cornwall (Coolie) . 



SCOTLAND. Folotry, Perth (Roy $ Bissett). Clova 

 Aits., Forfar ! 



IRELAND. Westmeath (Archer). 



G-<'< HJ,-. Distri.1>"flnii. Germany. Siam. Australia. 

 United States. 



C. Retnxcltii Arch, is a rare species which lias very seldom 

 been observed. Nordstedt, in his ' Index DesmicV 1896, p. 

 1858, states that C. limnophilum Schmidle is synonymous 

 with C. Reinschii Arch, but the few specimens we have seen 

 of the latter species do not possess the granulation described 

 and figured by Schmidle for C. limnophilum (vide Schmidle, 

 < Beitr. alp. Alg./ 1895, p. 457, t. 15, f. 20). 



Var. eboracense var. uov. (PI. LXVI, fig. 11.) 



Sides of semicells with five undulations, those near 

 the basal angles being much smaller than the upper 

 ones, apex truncate with two shallow undulations, 

 apical angles not rounded. Vertical view broadly 

 elliptic, without a median inflation. 



