ALGAL FLORA OF THE MISSOURI BOTANICAL GARDEN. 37 



Nostoc sp. Nelumbium pools. Sept. to Nov. Common. 

 Cylindrospermum minutissimum Collins. Nelumbium 

 pools. May and June. Common. 



SCYTONEMACEAE. 



Scytonema Hofmanni Agardh.* 



RIVULARIACEAE. 



Calothrix sp. Nymphaea pool on edge of cement basin. 

 Common. May, June. Associated with Stigeoclonium 

 aestivale, Chroococcus and Hydrodictyon. 



Flagellata. 



RHIZOMASTIGACEAE. 



Mastigamoeba aspera Schultze. 



* 



HYMENOMONADACEAE. 



Synura uvella Ehrenb. Arboretum pool. Sept., Oct 



Rare. 



OCHROMONADACEAE. 



Ehrenb. Arboretum pond. Rare 



Oct, 



Uroglena volvox Ehrbg.* 



CRYPTOMONADINEAE. 



Chilomonas sp.* 



I 



EUGLENACEAE. 



Euglena acutissima Lemm. Nymphaea pool. Rare. 



Euglena acus Ehrbg.* 



Euglena oxyuris Schmarda.* 



Euglena proxima Dangeard. Nymphaea pool. Arbore- 

 tum stream. Abundant, April, May, June. This species 

 was noted thickly covering the surface of the Nymphaea pool, 

 with a green scum. Many of the individuals were in motion, 

 though the scum consisted largely of those in resting state, 

 more or less enveloped in mucus and globular in form. At 

 intervals this scum appears on the mud at the edge of the 



Arboretum stream. 



