Beggiatoa. 



39 



Fig. 32. Beggiatoa pellucida, x 400 (after Cohn). 



55. B. mirabilis, Cohn (U, p. 81). 



Threads very thick, motile, bent and curled in various 

 ways, with rounded 

 ends, distinctly 

 jointed, as much as 

 1 6 n thick ; articu- 

 lations about half 

 as long as broad, 

 filled with nume- 

 rous, pretty large 

 granules. Threads 

 twisted round and 

 entangled with one 

 another, forming a 

 snow-white web of 

 gelatinous threads. 

 (Fig. 33-) 



With the preceding. 



Fig. ^.Beggiatoa mirabilis, X about 320 (after 

 Cohn). 



DOUBTFUL SPECIES. 



56. B. tigrina, Rabenhorst (" Flor. Eur. Alg.," ii. 



P- 95)- 



Oscillaria tigrina, Romer. 



Threads pretty thick, oscillating, distinctly jointed, with 

 blunt and slightly bent, sometimes abruptly attenuated 

 and crooked ends, translucent, 3 -5-4 -5 p. thick; forming thin 

 white layers. (Fig. 29^.) 



In marshes and on wood under water. 



