PENIU.M. 99 



Var. obtusum West & G. S. West. (PI. 10, fig. 2<u 



Penium curtum var. oMitsum West & G. S. West, Notes Al^. II, 19' m, 

 p. 289, t. 412, f. 1, 2 ; Alga-fl. Yorks. 1900, p. 47. 



Rather larger than the average size, with the sides 

 at the base of the semicells subparallel and with sub- 

 truncate apices, below which the sides are very faintly 

 hollowed. 



Length 41-45 A* ; breadth 20-2:^; breadth of 

 isthmus 10 /(. 



ENGLAND. Ingleton, AY. Yorks! 



-o. Penium rufescens Cleve. 

 (PI. VI, figs. 12, 13.) 



Penium rufescens Cleve, Sverig. Desra. 1864, p. 493, t. 4, f. 5 ; Eabcnh. 



Flor. Europ. Algar. Ill, 1868, p. 123 ; Lund. Desm. Stiec. 1871, p. s.5 ; 



Wille, Norges Ferskv. Alg. 1880, p. 50 ; Roy & Biss. Scott. Desm. 1MH. 



p. 253 ; Nordst. -Index Desm. 1896, p. 227 ; West & G. S. West, Alg. S. 



England, 1897, p. 479 ; Alga-fl. Yorks. 1900, p. 44. 

 Fe iiium rufopellitum Roy, Desm. Perthshire, 1877, p. 73; Cooke, Brit. 



Desm. 1887, p. 18.5 ; West, Alg. W. Ireland, 1892, p. 126. 



Cells rather under the medium size, 2-2^ times 

 longer than their diameter, cylindrical or very slightly 

 widening from the middle to the rounded apices, with 

 an exceedingly faint trace of a constriction in the 

 middle ; cell-wall dark brown or brick-red in colour, 

 A r ery minutely punctate ; the newer portions of the 

 cell-wall smooth and colourless, sometimes separating 

 from the old coloured portions ; chloroplasts with 

 many longitudinal ridges. 



Zygospore unknown. 



Length 00-72 n; breadth 23'5-2 ( J/i. 



ENGLAND. Bisley Common, Surrey ! Cronklev Fell, 

 X. Yorks ! 



SCOTLAND. Inverness, Aberdeen, Kincardine, Perth, 

 Argyll (1-foi/ $- Jtiswft). Loch Luichart, Ross ! 



IRELAND. Kylemore, Galway ! 



d'ciKjr. Distribution. Norway. Sweden. Brazil. 



In some specimens of this rare species the cell-Avail is con- 

 spicuously punctate, but in others it is not. 



