Beggiatoa. 



3; 



Var. marina, Cohn {B. CErstedtii, Rabenhorst). 

 Threads densely filled with blackish granules, only 2 ^ 

 thick. 



d 



Fig. 29. — a, Beggiatoa alha, X 600 ; ^, 5. nivea, with the 

 plasma contracted, X goo ; c, 5. leptomiH/armis, X 800 ; 

 rf, B. tigrina^ X 800 (a, c, and ^, after Kiitzing ; 3, after 

 Rabenhorst). The engraver has made these threads too 

 thick, especially c 



Forming a delicate snow- 

 white gelatinous membrane on 

 ,decaying animals and Algse in an 

 aquarium with sea- water. (Fig. 

 30-) 



51, B. nivea, Rabenhorst ("Flor. Eur. Alg.," ii. p. 94). 

 Leptonema niveum, Rabenhorst. 



Threads very slender, indistinctly jointed, i-i -5 ^ thick 

 (according to Rabenhorst), forming undulated woolly tufts 

 ,of a chalk-white colour. (Fig. 29^.) 



Fig. 30. — Beggiatoa alba, var. wia- 

 rina, X 660 (after Warming). 



