CLOSTEIUUM. IS 7 



Cells of medium size, 20-28 times longer tlian their 

 greatest diameter, almost straight, median part of cell 

 fusiform-lanceolate, outer and inner margins almost 

 equally convex, attenuated towards each extremity 

 into long, colourless, setaceous processes, apices slightly 

 incurved, rounded, and often slightly swollen; cell- 

 wall colourless or straw-coloured, striated, Hi IS striae 

 visible across the cell; chloroplasts with a median row 

 of four or five pyrenoids, terminating at the base of t lie- 

 apical processes ; terminal vacuoles large, situated at 

 the base of the apical processes, and containing from 

 six to nine moving granules. 



o O 



Zygospore siibrectaugular, sides straight or concave, 

 angles truncate or truncately rounded. 



Length 370-520 (even up to (iOO)^; breadth 10-23 /u; 

 breadth of apices 2*8-3*8 /x ; greatest breadth of zy go- 

 spore 48 51/x; shortest breadth of zygosp. 35-36 /x. 



ENGLAND. Westmoreland (zygosp. from Blea Tarn) ! 

 Lancashire ! W. and N. Yorks ! Cheshire, with 

 zygosp. (Roy"). Leicester (Hoi/}. Essex! Suffolk! 

 Cambridge ! Oxford (zygosp. from near Goring) ! 

 Surrey! Hants! (l>V////r/7). Cornwall! 



WALES. Llyn Idwal ! , Llyn Ogwen ! , Capel Curig 

 (with zygosp.) ! , Llyn Gwynant ! , and Llyn Padarn, 

 Carnarvonshire ! Llyn Coron, Anglesey ! 



SCOTLAND. Sutherland ! , Ross, Inverness, Aber- 

 deen ! , Kincardine, Forfar ! , Fife ; zygosp. from near 

 Gillan in Strachan, Kincardine (J!t/ $ Bissett). Harris 

 and Lewis, Outer Hebrides ! In the plankton of Loch 

 Tay and Loch Achray, Perth ! , and of Loch Doon, Ayr ! 



IRELAND. Donegal ! Galway ! Kerry (zygosp. from 

 Kylemore) ! 



Geot/r. Distribution. France. Germany. Austria 

 and Galicia. Norway. Sweden. Bornholm. N. and 

 Central Russia. Faeroes. Greenland. India. Ceylon. 

 Siam. Australia. New Zealand. Central Africa 

 (var.). Madagascar. United States. Brazil. Ecuador. 

 Paraguay. Patagonia. 



Cl. Kutzingii is a moiv elegant species than 67. rast rat tun, 



