- 164 — 



23. P. mimitissimum Nordst. in Acta Univ. Lund. 1873, tom. IX. 

 p. 46, t. I, f. 21. 



Long. 17^; lat. 10,6 fjt. 



In stagnant water in riverbed. 

 Area: Europe, Madagascar, Burmah. 



24. P. inconspicuum West in Journ. Roy. Micr. Soc. 1894, p. 4, 

 t. 1, f. G, 7. 



Long. 17//; lat. 6 /i. 



Amongst other Desmids in stagnant water. 

 Area: Europe and N. America. Ceylon. 



Closterium Nitzsch. 



25. C. prælonguin Bréb. in Mém. Soc. Scient Nat. Cherbourg, 1856, 

 IV, p. 152, t. 11, f. 41. 



Long. 459 — 625^; lat. 16,5 — 18/;. 

 In stagnant water in the jungle. 



Area: Europe and N. America. New Zealand (forma). 



26. C. acerosum Ehrenb. in Abhandl. Akad. Wissenschaft. Berlin 

 1831, p. 68; Ralfs Brit. Desm. 1848, p. 154, t. XXVII, fig. 2. 



Forma apicibus truneatis ; membrana luteo-brunnea, subtilissime 

 striolata. Long. 436— 583 p ; lat. 45 ^ ; lat. apic. 8 — (Tab. nostr. 

 II, fig. 5.) Diam. zygosp. 87/*. 



The apices were much more truncate than in var. truncatum Gutw. 

 (in Spraw. Kom. fizyjogr. Akad. Umiej. Krakow. 1891, p. 33, t. 1, f. 7); 

 in fact, Gu twins ki's variety appears -to be very little different from the 

 typical form. 



Area: Ubiquitous. 



27. C. Lunula Nitzsch 1817; Ralfs Brit. Desm. 1848, p. 163, t. XXVII, 

 f. 1. Vibrio Lunula Müller 1784. 



Var. sublanceolatum Klebs in Schrift, phys.-oekon. Gesellsch. Königs- 

 berg V, 22, 1879, p. 6, t. 1, f. 1 e et f. 



Forma minor, cellulis paullo angustioribus; membrana lutea, glabra. 

 Long. 282 /;; lat. 32,5^; lat. apic. 8,5 p. 



This form approaches Very closely to the plant mentioned and figured 

 by Gut wins k i as CI. acerosum Ehrenb. forma (Roypraw. Wydz. matem.- 

 przyr. Akad. Umiej. Krakow. 1896, tom. XXXHI, p. 36, t. V, f. 6). 



Area of type: Europe, N. and S. America, E. Africa, India, Central Asia, 

 Japan, New Zealand and Australia. 



28. C. Ehrenbergii Menegh. Synops. Desm. in Linnæa 1840, p. 232; 

 Ralfs Brit. Desm. 1848, p. 166, t. XXVIII, f. 2. 



