38o BACTERIOLOGY 



Habitat. Found in dirty water, drain water from sugar factories, sulphur 

 springs, etc. The filaments are attached to decayed plants, etc., pro- 

 ducing slimy flakes. 



2. Beggiatoa arachnoidea (Agardh) Rabenhorst 



Flora, 1827, 634. 

 Found in swamp water, also in sea water. Filaments 7 microns thick. 



3. Beggiatoa mirabilis Cohn 



Hedwigia, 1865, 81. 



Filaments 16 /a thick. Found in sea water, forming white growths on dead 

 algae, etc. 



4. Beggiatoa roseopersicina Cohn 



Beitrage Biol., I, 3, 1875, 157. 



Filaments like (i), but colored as above. Found in stagnant water, forming 

 a surface growth of a red violet color. 



