Spirillum. 5 1 



Var. robustum, Warming (I.e., Resume, p. 23). 



Thickness 2-4-5 /* height of the spirals 10-20 p., 

 diameter 1-3 /x. Usually with i^ turn. Sometimes with 

 two flagella at one end. (Fig. 50.) 



In sea- water. 



Fig. 50. Spirillum volu- 

 tans, var. robustum, X 

 660 (after Warming). 



Fig. 51. Spirillum sanguine* 

 X 600 (after Koch). 



73. S. sanguineum (Ehrenberg), Cohn (" Beitrage," 



i. p. 171). 

 Ophidomonas sanguined, Ehrenberg. 



Cells cylindrical, only seldom attenuated at the ends, 

 3 fi or more thick, of various lengths, with usually 2 (seldom 

 ^ or 2^) spirals. Height of the spirals 9-12 /i, diameter 

 about of the height ; a flagellum at each end. Cell- 

 contents coloured by numerous reddish bodies, with many 

 sulphur granules. (Fig. 51.) 



In putrefying brackish w r ater [and pond water?]. 



According to Warming, the longest specimens reach 65 ji. ; the 

 height of the spirals I5~37 M> while the diameter amounts to 3 or , or 

 in small specimens \ - T ' ? of the height. 



[According to Saville Kent, the Ophidomonas sanguined of Ehrenberg 

 is a true monad, and not identical with Cohn's Spirillum sanguineum. 

 (See " Manual of the Infusoria," p. 244, and infra, p. 94.) TR.] 



