KAARE MUNSTER STRØM. 



In outline this species resembles some of the large plankton- 

 forms of Cosmarium depressum var. achondrum found in the 

 Caledonian plankton, but the chloroplast is of an entirely differ- 

 ent nature. 



It seems to be principally an Australasian form. 

 Cosmarium crenatutn Ralfs. 

 Ralfs: Brit. Desmid. 

 Rare. 

 Cosmarium granatum Ralfs. 



Ralfs: op. c. 

 This ubiquitous species was very common. 

 Cosfnarium lœve Rabh. 



Rabenhorst. Flor. Eur. Algar. 

 Scarce. 

 Cosmarium Meneghinii Breb. 

 Brébisson apud Ralfs: Brit. Desm. 

 Rare. 

 Cosmarium multiordinatum var. Burmense W. & G. S. 

 West. 



W. & G. S. West : Freshvv. Algæ Burma. 

 This very interesting and rare Desmid was represented with 

 a few specimens. The variety Burmense seems to be one of 

 the numerous Desmids with a characteristic Indo-Malayan 

 distribution. 



The species and the var. Burmense are very characteristic, 

 and should never be confused with any other species. — The 

 warts at the margins of the semicells are conical, and the small 

 pits between the 'granules are rounded, and not angular as in 

 so many other tropical forms of Cosmarium. 



Cosmarium punctulatum var. subpunctulatum Boerges. 

 BøRGESEN : Ferskv. Alg. Østgrønland. 

 Quite common. 

 Cosmarium reniforme var. compressum Nordst. 

 Nordstedt: Freshw. Algae New Zealand. 



