OXYCHONEMA. 215 



Cells small, slightly broader than long, constriction 

 fairly deep, sinus oval in shape, semicells narrowly 

 oblong, angular, -sides truncate with a granule at each 

 angle, apex slightly convex ; semicells with 2 granules 

 placed symmetrically on each broad face ; cells in 

 lateral view very slightly constricted, semicells rounded, 

 with 2 granules in a vertical series. 



Zygospore unknown. 



Length 15-16^; breadth 16- 17 a.; thickness 8 (x ; 

 breadth of isthmus 6-7 y. . 



SCOTLAND.- -Inverness, Aberdeen and Kincardine (Roy 

 & Biss.). 



Geoyr. Distribution. Sweden. Denmark. Bengal. 

 Australia (form). United States. Brazil (form). 



Var. anglicum W. & G. S. West. (PI. CLX, figs. 



10, 11.) 



Sph. ]\'iillic/tii var. <(iit//i<:iii West & G. S. West, Alg. S. England, 1897, 

 p. 497, t. 15, f. li. 



Apex of semicell slightly convex, sinus smaller than 

 in the type, with 2 or 3 granules on the lateral margins 

 of the semicells, and others scattered sparsely and 

 irregularly across the surface. 



Length 10-ir5 k u.; breadth lO'5-ll u. ; breadth of 

 isthmus 6 JJL ; thickness o '5 u.. 



ENGLAND. --Xew Forest, Hants ! (Abundant July, 

 1897.) 



Genus 22. ONYCHONEMA Wallich, 1860. 



Wallich, Desm. Low. Bengal, 1860, p. 194. 



Cooke, Brit, Desm. 1887, p. 6. 



De Toni, Syll. Alg. 1889, p. 795. 



Wille in Engl. Naturl. Pflanz. Fam. 1890, p. 14. 



Turn. Freshw. Alg. E. India, 1893. 



G. S. West, Brit, Freshw. Alg. 1904, p. 175. 



Cells small, forming simple filamentous colonies, com- 

 pressed, deeply constricted, sinus narrow ; semicells 

 elliptic or reniform, sometimes with strong lateral 



