FLElTlinT.KMI M. 



213 



gradually attenuated to the apices, which are dilated 

 and rounded-truncate. 



Length 544-628 /A; breadth at base of semicclls 

 _!'! 23-") /A; breadth, of apices 14 /A. 



SCOT i, A XD. Rhiconich, Sutherland ! 



7. Pleurotaenium maximum (Reinsch) Lund. 

 (PI. XXXI, figs. 1, 2.) 



Doridinm nuixitinnti Reinsch, Spec. Gen. Alg. 1867, p. 140, t. 20 C II, f. 1, - ; 



Al-mfi. Frunken, 1807, p. 184, t. 12, f. 4 ; Roy & Hiss. Scott. Dosm. 



IS'JL, p. 241. 

 Pleurotaenium itni,i-iiiiniii (Reinsch) Lund. Desni. Suec. 1S71, p. ^!( ; Hi 1 



Toni, Syll. Alg. 1889, p. 899; Nordst. Index Desin. 1S90, p. 100; West 



\ <i. S. West, Welw. Afric. Fresliw. A1-. ls97,p. 80; Fiv.slnv. ChL.rophy. 



Koh Chany, 19O1, p. 107 ; Freslnv. Aly. Ceylon, 19<)2. ].. 145. 

 Pic" >-<it;t'tiiinit Ari-Jicrii Delp. Ilcsni. Sulialp. 1N77, p. 128, t. 19, f. 12-16; 



Wille, Sydamerik. Algfl. 1884., p. 23 ; De Toni, Syll. Aly. 1889, p. 902 ; 



Liitkem. Desm. Attersees, 1893, p. 540. 

 Docidium Archerii (Delp.) Wolle, in Bull. Torr. But. Club. 1885, p. 2. 



Cells large, subcylindrical and elongated, 14-18 

 times longer than their diameter ; semicells with a 

 prominent basal inflation and often with a smaller 

 undulation immediately above it, very slightly tumid 

 and then gradually tapering to the apices, which are 

 truncate with rounded angles ; cell-wall punctate. 



Zygospore unknown. 



Length 568-852 ^ ; breadth at base of semicells 

 38-54/A; breadth in middle of semicells 31-42 ^ ; 

 breadth of apices 22-30 p. 



WALES. Capel Curig, Carnarvonshire ! 



SCOTLAND. Scolty, near Banchory, Kincardine 

 Bisxcff). Aberdeen ! 



Distribution. France. Grermany. Italy. 

 Austria and Glalicia. Hungary. Sweden. Japan (var.). 

 Ceylon. Siam. Abyssinia. W. Africa. Brazil. Ecuador 

 (var.). Paraguay. Uruguay. 



This species differs very little from PI. Tnilir<-n/<i, ln-ing 

 distinguished by its Iju-^er si/e ;ind the greater prominence of 

 the basal intiatiuii of the semicells. Jt is one of the hirers! 

 and likewise one of the rarest Desmids which occur in the 

 British Islands. 



