- 181 — 



97. H. dissiliens Bréb. in Ralfs Brit. Desm. 1848, p. 51, 1. 1, f. 1. 

 Lat. 16— 18/i; diam. zygosp. 19 — 22//. 



In stagnant water in riverbed among various species of Spirogyra, 

 with zygospores. 



Area: Ubiquitous. 



Ord. Protococcacece. 



Fam. Palmellaceæ. 

 Cœlastrum Nag. 



98. C. sphæricum Näg. Gatt, einzell. Alg. 1849, p. 98, t. V, f. Gl. 



In stagnant water in the jungle. 



Area: Europe, N and S. America, W. Indies, Madagascar, India, Sumatra, 

 Siberia, New Zealand. 



99. C. pulehruiii Schmidle in Bericht, d. d. Botan. Gesellsch. Bd. X, 

 1892, p. 206, t. XI, f. 1. 



Var. intermedium Bohlin in Bih. till K. Sv. Vet.-Akad. Handl. Bd. 23, 

 no. 7, 1897, p. 35, t. II, f. 16, 17. 



In stagnant water in the riverbed. 



Area (of type): Europe, S. America, Ceylon, Queensland. 



Pediastrum Meyen. 



100. P. duplex Meyen. P. perhisum Kiitz. P. Napoleoms Ralfs 

 Brit. Desm. p. 184, t. XXXI, f. 7. 



With the preceding species abundant. 

 Area: General in temperate and tropical regions. 

 Var. <iat lira tu m A. Br. Alg. Unicell. p. 93. 

 With the typical form. 



101. P. Tetras (Ehrenb.) Ralfs in Ann. Mag. Nat. Hist. XIV, 1844, 

 p. 469, t. XII, f. 4. Micrasterias Tetras Ehrenb. 1838. 



With the preceding species and very abundant. Coenobia of 4, 1 + 7 and 

 5 + 11 cells. 



Area: Ubiquitous. 



Scenedesmus Meyen. 



102. S. bijugatus (Turp.) Kiitz. Syn. Diat. 1333, p. 607. Achnan- 

 thes bijuga Turp. 



Abundant in stagnant water in the jungle and in muddy ricefields. 

 Area: Ubiquitous. 



103. S. denticulatus Lagerh. in Öfvers. af K. Vet.-Akad. Fork 1882, 

 no. 2, p. 61, t. II, f. 13-16. 



