THE LEUCO-THIOBACTERIA 



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Thioploca ingrica (Wislouch), 1912. 



Literature. — Wislouch (i), 191 2 ; Kolkwitz (7), 1912 ; 

 Koppe, 1923 ; Bavendanim, 1924. 



Description. — The rope-Uke masses which constitute this 

 species are white in colour, are about i centimetre long, and 

 are composed of threads rich in sulphur. The threads creep 

 along both directions of the longitudinal axis. Each rope 

 contains from ten to twenty threads, some with blunt, others 

 with pointed ends. 



Habitat. — Same as preceding species. Has been found in 

 Leningrad, in a harbour in the Gulf of Dantzig (Frisches Haff), 

 and in the Boden See (Switzerland). 



The differences between the two species of this genus may 

 be tabulated as follows : — 



Recently two species of this genus have been described 

 by Koppe, and named respectively Thioploca minima and 

 Thioploca mixta. As the distinction between them and the 

 two preceding species is confined to a difference in dimensions 

 only, and as they are found mixed with Thioploca ingrica, 

 and as in Thioploca mixta different thicknesses of thread are 

 found in the same colonies, we are entitled to conclude that 

 these latest additions are merely variant forms of Thioploca 

 ingrica. 



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