Cl.nSTKI.'llTM. 1 o'.l 



Cells small, 8-10 times longer than their diameter, 

 strongly curved, outer margin 125-lor) D of are, inner 

 margin not tumid, gradually attenuated, to the apices, 

 which are subacute or acutely rounded ; cell-wall 

 smooth and colourless; chloroplasts with a single series 

 of about four pyrenoids. 



Zygospore globose, furnished, with mammillate or 

 conical projections, nine or ten of which show in the 



margin. 



Distance between apices 7 7-1 08 /A; breadth 0-1 2 /A; 

 diam. zygosp. without projections 18-20 /A, with pro- 

 jections 2-5--J2 fji. 



ENGLAND. Delaniere, Cheshire (!!<>>/). Enbridge 

 Lake, Hants (J {<>//]. 



WALES. Bettws-y-coed and Glyder Fawr, Carnar- 

 vonshire (Rot/), 



SCOTLAND. General ; zygosp. from near Dinnet, 

 Aberdeen, and Glen Dye, Kincardine (Ituy $- J.ti.wfl). 

 Harris, Outer Hebrides ! Orkneys ! 



IRELAND. Dungloe, Doocharry Bridge, near Glenties, 

 and Lough Machugh, Donegal ! Dublin and Wicklow 

 (Archer). 



Geogr. Distribution. France. Galicia in Austria, 

 Sweden. Poland. N. Russia. Nova Zeinbla. Ceylon. 

 Siam. Brazil (var.). Paraguay (var.). 



This species differs very little in its sterile condition from 

 ('I. par ml n in, having the same curvature but being a little 

 smaller. The cell-wall was described by Wittrock as very 

 delicately striated, but we doubt whether these st nation.- 

 have ever been detected since they were originally described. 

 \Ve have, therefore, described the cell-wall as "smooth." 

 It is a species which has most probably been greatly over- 

 looked, chiefly 011 account of its close resemblance to ( 'I. 

 p<in'nli.iiit, but when found in the conjugated state the zygo- 

 spores are eminently characteristic. 



Forma major West and (I. S. West. (PI. XVI, 



figs. 5, (i.) 



Cl. rn/ns/ioni/ii i'orma mn/or AVest and G. S. West, New and Int. Freslnv 

 Al--. 1SUG, p. 152, t. 3, f. 25, 2(3; Nordst. Index Dc-sui. 1.SSM5, p. 275; 

 West & G. S. West, Alg. S. England, IS'.-T, p. 1M. 



