62 BRITISH DESMIDIACEJ1. 



More cylindrical than the typical form and almost 

 twice the size ; sometimes unconstricted, but more 

 often with a slight constriction. 



Length 102-114^; breadth 48-54 ,. 



ENGLAND. Pilmoor, X. Yorks ! Riccall Common, 

 E. Yorks ! 



SCOTLAND. Deeside, Aberdeen (Roij fy ///x.s-r//). 



|I;KLAXD. Lakes, from Clifden to Roundstone, Gal- 

 way ! 



Roy and Bissett found in Kincardine at Dalbrake in 

 Strachan a smaller form of this variety which was the exact 

 counterpart of the large one except for size; length 56 n ; 

 breadth '25 /j. They also remark that "when seen side lv 

 side in the same gathering with ( '. dipl oxford it looks verv 

 ditferent from that species." 



5. Cyliiidrocystis roseola Turn. 

 (PI. IV, fig. 39.) 



alis roseola Turn. Desm. Notes, 1893, p. 3-16, t'. 18 ; Nurdst. 

 Index Desmid. 1896, p. 225. 



Cells subcylindrical, about 2^ times longer than 

 their diameter, with a gradual constriction in the 

 middle of the cell, attenuated towards the apices which 

 are rounded and slightly thickened ; cell-wall smooth, 

 yellowish-pink or bright pink in colour. 



Zygospore unknown. 



Length 4(5-52^; breadth 1D-21 /u. 



WALKS. Near Dolbadarn Castle, Carnarvonshire 

 (W. B. Turner). 



0. Cylindrocystis minutissima Turn. 

 I. V, fig. 9.) 



M/nir//*/i'.s iiiin it/issnint Turn. Fivshw. Al^\ E. India, 181)3, p. Ki, t. 1, 

 f. 21.; West \ <i. S. West, Alg. N. Ireland, 1902, p. 20; Fmshw Al"-. 

 Ceylon, 1902, p. 13-1. 



Cells minute, about twice longer than the diameter, 



