ONYCHONEMA. 217 



Scott. Desm. 1893, p. 11 ; West & G. S. West, Alga-fl. Yorks. 1902, 

 p. 110; Alg. N. Ireland, 1902, p. 59; G. S. West, Brit. Freshw. Alg. 

 1904, p. 175, f. 67, G, H. 



Onychonema fill for me Roy & Biss. Jap. Desm. 1886, p. 242 ; Nordst. 

 Freshw. Alg. New Zeal. 1888, p. 29, t, 2, f. 10 ; De Toni. Syll. Alg. 1889, 

 p. 786 ; Anders. Sverig. Chloroph. 1890, p. 9 ; West, Notes Dan. Alg. 



1891, p. 1 ; West, Alg. W. Ireland, 1892, p. 116 ; Alg. Eng. Lake Distr. 



1892, p. 6 ; Roy & Biss. Scott. Desm. 1893, p. 11 : West & G. S. West, 

 Alg. S. England, 1897, p. 497 ; G. S. West, Brit. Freshw. Alg. 1904, p. 175 ; 

 Kaiser, Alg. Traunstein u. Chiem. 1914, p. 153. 



Xjthcerozosma vertebratum Hauptti. Zellm. u. Hullgallerte Desm. 1888. p. 21 

 (sep.), t. 2, f. 16-23, 27. 



Cells small, about as long as broad, deeply constricted, 

 sinus narrow, almost linear ; semicells elliptical or sub- 

 reniform, ventral nwrgin almost straight, dorsal margin 

 broadly rounded ; semicells with two long processes, 

 nearly as long as the semicell itself ; disposed asymmetric- 

 ally, and overlapping the adjacent cell of the filament 

 (only one of the processes of any semicell is seen in the 

 front view, the second one being on the opposite side of 

 the filament). Cells united to form long twisting fila- 

 ments, the cells often separated from each other by a 

 greater or smaller space. 



Zygospore unknown. 



Length, not including processes, 9-12*5 JJL ; breadth 

 1 0-12*5 fx ; thickness 5-6*4 \L ; breadth of isthmus 3*5-4 u. 



ENGLAND.- -Bowness, Westmoreland ! Pilmoor and 

 Strensall Common (W. B. Turn.}, N. Yorks! Skipwith 

 and Riccall Commons, E. Yorks ! Dartmoor, Devon 

 (Harris). Gunwen Moor, Cornwall ! 



WALES. Capel Curig, Carnarvonshire ! 



SCOTLAND.- -Xear Strathpeffer, Eoss ; Lochs Ruthven, 

 Aschie, Coire, near Brin, Inverness ; Aberdeen and 

 Kincardine (Roy & Biss.). Ehiconich, Sutherland ! 



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

 Eoundstone, Mayo ! Lakes near Eecess, Clifden and 

 Derryclare Lough, Galway ! Tipperary (Arch.). Ulster, 

 Minister and Connaught (Adams). 



Geogr. Distribution.- -France. Germany. Galicia in 

 Austria. Sweden. Denmark. Bornholm. Poland. 

 Japan. Celebes. India. New Zealand. Australia. 

 Tasmania. United States. Colombia. 



