— 179 — 



In muddy ricefields. 



Area: Europe, N. America, E. Africa, India, Java, New Zealand and 

 Australia. 



89. S. hexacerum Wittr. in Bih. till K. Sv. Vet.-Akad. Handl. 1872, 

 Bd. 1. no. 1, p. 51. Desmidium? hexaceros Ehrenb. 1833. S. tricorne 

 Menegh. 1840; Ralfs Brit. Desm. 1848, p. 134, t. XXII, f . 1 1 a et c,, 

 t. XXXIV, f. 8 «. 



Var. tropicum West & G. S. West, n. var. (Tab. nostr. Ill, fig. 30). 



Var. semicellulis elliptico-fusiformibus, ventre convexiori quam 

 dorso; granulis minutissimis in seriebus trans angulos. 

 Long. 16//; lat. 20//.; lat. isthm. 5,4//, 



This is probably identical with the form figured from Sumatra by 

 S c h m i die as S. pygmœum Bréb. var. obtusum Wille. 



In muddy ricefields. 



Area (of type): Europe, N. and S.America. W. and E.Africa, Madagascar, 

 Japan, New Zealand. 



90. S. micron West & G.S.West in Journ. Roy. Micr. Soc. 1896, 

 p. 159, t. IV, f. 50, 51. 



Forma spinis reductis et numerosioribus. (Tab. nostr. Ill, fig. 38.) 

 Long, cum proc. 16 — 17,5//.; lat. cum proc. 19 — 31 // ; lat. isthm. 

 5 — 5,5 /a. 



In stagnant water in the jungle. 

 Area: Europe, W.Africa (var.). 



91. S. pseudotetracerum West, et G. S. West in Trans. Linn. Soc. 

 bot. ser. 2, V, 1895, p. 79, t. VIII, f. 39. S. contortum Delp. var. pseudo- 

 tetracerum, Nordst. in Kongl. Sv. Vet.-Akad. Handl. Bd. 22, no. 8, p. 50, 

 t. V, f. 14. 



Var. robustuiti West & G. S. West, n. var. (Tab. nostr. III, fig. 32 

 -34.) 



Var. cellulis (sine processibus) paullo longioribus, processibus 

 brevioribus: a vertice visis 4-radiatis. 



Long, sine proc. 16 — 20 /*, cum proc. 19—25 t u ; lat. sine proc. 

 cire. 9,5—13 fi, cum proc. 17 — 26 fi\ lat. isthm. 5,5 — 6 fi. 



With the preceding species. 



Area (of type): N. America, Madagascar, Ceylon, New Zealand. 



92. S. margaritaceum Menegh. Synops. Desm. in Linnæa 1840, p. 227 ; 

 Ralfs Brit. Desm. 1848, p. 134, t. XXI, f. 9. 



Forma 5-gona. 



In stagnant water amongst ISpirogyra decimina var. 

 Var. robustum West & G. S. West in Journ. Roy. Micr. Soc. 1897, 

 p. 496, t. VII, f. 14. 



