C'LOSTKiaUM. 



22. Closterium Leibleinii Kiitz. 

 (PL XVI, figs. 0-14.) 



Closterium Leibleinii Kiitz. Syn. Diat. 1834, p. 596, t, 18, f. 70; M.-nt'gh. 

 Synops. Desin. 18 H), p. 232 ; Ralfs, Brit. Desm. 1848, p. KJ7, t. 28, f. 1 : 

 Kiit/. Spec. All?. IS!!), p. 163 ; Arch, in Pritdi. Iiifus. 1861, p. 74s, t. 2, 

 f. 1,5; Rabenh. Flor. Europ. Alg-ar. Ill, 18(38, p. 132; W..1K Drsm. 

 U S 1884, p. 4(5, t. 7,f. 13, 14,20; Cooke, Brit. Desm. 188(5, p. 25, t. 13, 

 f. 1 ; De Toni, Syll. Algar. 1889, p. 846 ; West, Alg. W. Ireland, 1892, p. 

 122 Roy & Biss. Scott. Desm. 1894, p. 246; Nordst. Index Desm. 1896, 

 p 156; West & G. S. West, Alg. S. England, 1897, p. 481; G. S. West, 

 Alga-fl. Cambr. 1899, p. 112 ; West & G. S. West, Alga-fl. Yorks. 19UO, 

 p. 50 ; Alg. N. Ireland, 1902, p. 23. 



Cl. Leibleinii var. Ralf's, Brit. Desm. 1848, p. 167. 



Cl. monilifennn Ehrenb. forma A.. Leibleinii Reinsch, Algenfl. Frank. 1867, 

 p. 190.' 



Cl. tnnnilif'erum Ehrenb. forma Leibleiniana Jacobs. Desm. Danem. 1875, 



p. 170. ' 

 Cl moniliferum Ehrenb. b. Leibleinii Klebs, Desm. Ostpretiss. 1879, p. 9, 



t. 1, f . 7. 

 Arthrodia Leibleinii Kiintze, Revis. gen. plant. 1891, p. 883. 



Cells of medium size, 6-8 times longer than their 

 diameter, strongly curved, outer margin 135-190 of 

 arc, inner margin strongly concave, slightly tumid in 

 the median part, gradually attenuated towards the 

 apices, which are acutely rounded ; cell-wall smooth 

 and colourless, more rarely straw-colour or yellowish- 

 brown ; chloroplasts with about six ridges and a median 

 row of 3-8 pyrenoids; terminal vacuoles large, with 

 a number of moving granules. 



Zygospore subglobose and smooth. 



Distance between apices 107-202 /A; breadth 17-37/x ; 

 diam. zygosp. 40-50 /A. 



ENGLAND. Westmoreland ! (7?/*.sr//). W., N., and 

 E. Yorks! Lancashire! (R1fa). Cheshire (/.W/x). 

 Leicester (7fr>?/). Essex ! Cambridge ! Oxford 

 (zygosp. from near Goring) ! Warwick (Wills). 

 Gloucester! (Rnlfi). Middlesex! Surrey! (Ralfs). 

 Sussex (Ralfa). Hants! Devon! Cornwall! (R<i //;-); 

 zygosp. from Penzance (Joshua). 



WALES. General ! 



SCOTLAND. Common ! ; frequently in conjugation 

 (Roij $' 13 i* sett). Lewis, Outer Hebrides! Shetlands ! 



IRELAND. Donegal! Mayo! Gal way! Kerry! Dublin 

 and Wicklow (ArrJirr). Down ! Lough Neagh ! Antrim! 



