GARDEN 



45 



angled mucronate-tipped form. De Toni in his summation 

 of the varieties lists T. trigonum (Nag.) Hansg. and T. cau- 

 datum (Corda) Hansg. He does not include Polyedrium 

 trigonum var. pentagonum Rab. or any equivalent. 



Tetraedron caudatum (Corda) Hansg. Nymphaea pool. 

 Rather rare. Apr., May. 



HYDRODICTYACEAE. 



Hydrodictyon retlculatum (L.) Lagerheim. 



Waterfall 



stream. Nelumbium pool. Apr., May, June. Rather com- 



mon 



Pediastrum Borya 

 Nymphaea pool. Co 



urp.) Meneg. Fountain pond 

 Sept., Dec, March to June. 



Pediastrum duplex Meyen. Fountain pond. Nelumbium 



pools. 



ymp 

 rum 



Nyn 



pool. Sept. to Dec, Mar. to June. Rare. 

 is (Ehrenbg.) Ralfs. Nelumbium pools. 

 Fountain pond. Sept., Mar., Apr., May. 



common 



ULOTHRICACEAE. 



Microspora stagnorum (Kiitz.) Lagerheim. Arboretum 

 pond. Associated with Spirogyra and Sticho coccus. Akin- 

 etes produced in the early part of April. Abundant. Mar., 



Apr., May. 



Stichococcus subtilis (Kiitz.) Klercker. Earth near Foun- 



tain pond. 



(El) 



Apr., May. Rather common. 



OEDOGONIACEAE. 



Fountain pond. Lagoon Waterfall 

 stream. Arboretum stream. Abundant. Sept. to June. 



mum sp 



produced 



They 



were enclosed in a delicate enveloping sac in which they came 



m which thev escaped in a tew min 



utes. Sexual reproduction beginning in June. 



Bulbochaete sp. Fountain pond. Sept., Oct., Nov. Rare. 



Ulothricales. 



CHAETOPHORACEAE 





Chaetophora elegans (Roth) Agardh. Attached to stems 

 of Juncu8, mixed with filamentous algae. Arboretum pond. 



Apr., May. Rare. 



