380 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 fi thick. Found in sea water, forming white growths on dead 

 alga;, etc. 



4. Beggiatoa roseopersicina Cohn 



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



Filaments like (1), but colored as above. Found in stagnant water, forming 

 a surface growth of a red violet color. 



