spirillum. 



51 



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



Thickness 2-4*5 /*> height of the spirals 10-20 fi, 

 diameter 1-3 ju. Usually with i^ turn. Sometimes with 

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



In sea-water. 



Fig. 50 — SpiriUuin volu- 

 taTtSf var. robustum, X 

 660 (after Warming). 



Fig. 51. — Spirillum sanguineum, 

 X 600 (after Koch). 



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

 i. p. 171). 

 Ophidomonas 'sanguinea, Ehrenberg. 



Cells cylindrical, only seldom attenuated at the ends, 

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

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

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

 contents coloured by numerous reddish bodies, with many 

 sulphur granules. (Fig. 51.) 



In putrefying brackish water [and pond water ?]. 



According to Warming, the longest specimens reach 65 fn ; the 

 height of the spirals 15-37 jti, while the diameter amounts to ^ or §, or 

 in small specimens ^--j^ of the height. 



[According to Saville Kent, the Ophidomonas sanguinea 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.] 



