— 179 — 
In muddy ricefields. 
Area: Europe, N. America, E. Africa, India, Java, New Zealand and 
Australia. 
89. §. hexacerum Wittr. in Bih. till K. Sv. Vet.-Akad. Handl. 1872, 
Bd. 1. no.1, p. 51. Desmidium? heaaceros Ehrenb. 1833. ° S. tricorne 
Menegh. 1840; Ralfs Brit. Desm. 1848, p. 134, t. XXII, f.11 a@ et 2, 
t. XXXIV, f. 8 a, . 
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 2; lat. 20; lat. isthm. 5,4, 
This is probably identical with the form figured from Sumatra by 
Schmidle-as S. pygmawm Bréb. var. obtusum Wille. 
In muddy ricefields. 
Area (of type): Europe, N. and S. America, W. and E. Africa, Madagascar, 
Japan, New Zealand. 
90. §. micron West & G.S. West in Journ. Roy. Micr. Soc. 1896, 
p. 159, t. IV, f. 50, 54. 5 
‘Forma spinis reductis et numerosioribus. (Tab. nostr. Ill, fig. 38.) 
Long. cum proc. si lat. cum proc. 19—21 yw; lat. isthm. 
5—5.5 pe 
‘In- stagnant water in the cant 
Area: Hupp, W. Africa (var.). 
S. pseudotetracerum West. et G. S. West in Trans. Linn. Soc. 
fot ser. 2, V, 1895, p. 79, ‘t. VI, £39. S. contortum Delp. var. pseudo- 
tetracerum Nordst. in Kongl. Sv. Vet. -Akad. Hand]. Bd. 22, no. 8, P. 50, 
t. v, f. 14. 
"Var. ‘robustum West & G.S..West, n. var. (Tab. nostr. IIL, ne 32 
— 34.) 
Var. cellulis (sine processibus) -paullo longioribus, processibus 
brevioribus::a vertice visis 4-radiatis. 
'. Long. sine proc. 16—20 », cum proc. 19—25 yp; lat. sine proc. 
circ. 9,5—13 yz, cum proc. ‘1/26 yp; lat. isthm. 5,5—6 yp. 
With the preceding species. 
Area (of type): N. America, Madagascar, Ceylon, New Zealand. 
92. §, margaritaceum Menegh. Synops. Desm. in Linnea 1840, p. 227; 
Ralfs Brit. Desm. 1848, p. 134, t. XXI, f. 9. 
Forma 5-gona. 
In stagnant water amongst Spirogyra, decimina var. 
Var. robustum West & G. S. West in Journ. Roy. Micr. Soc. 1897, 
p. 496, t. VI, f. 14. 
