FAMILY chla:mydobacteriaceae 



983 



Habitat: Swamp water or sewage pol- 

 luted waters. 



Appendix: Additional species have 

 been described as belonging in this genus. 

 Those described by Ravenel have gener- 

 ally' been overlooked although he was 

 one of the earliest workers to culture 

 these organisms. The list follows: 



Cladothrix fungiform is Ravenel. 

 (Mem. Xat. Acad. Sci., 8, 1896, 19.) 

 From deep virgin soil. 



Cladothrix inteslinalis Ravenel {loc. 

 cit., 18). From virgin soil. 



Cladothrix non-liquefacicns Ravenel 



{loc. cit., 16). From deep made soil. 



Cladothrix -profundus Ravenel Hoc. 

 cit., 17). From deep made soil. 



Cladothrix ramosa Gasperini. (Atti 

 d. Soc. toscana d'Ig., 2, 1912, 000.) 

 From water. 



Cladothrix reticularis Xaumann. 

 fKungl. Svenska Vetenskapsakad. 

 Handl., I, 62, Part 4, 1921, 44; Sphaero- 

 iilus reticularis Cataldi, Thesis, Univ. 

 Buenos Aires, 1939, 55.) From Aneboda 

 region, Sweden. 



Sphaerotilus 7-oseus Zopf. fBeitriige 

 z. Phj'siol. u. Morph. nieder. Organis- 

 men. 1892, 32.) From water. 



Genus II. Clonothrix Rozc. 



(Jour. d. Bot., 10, 1896, 325.) From Greek klon, a twig and thrix, hair. 



Attached filaments showing false branching as in Sphaerotilus. Sheaths organic, 

 encrusted with iron or manganese, broader at the base and tapering toward the tip. 

 Cells colorless, cylindrical. Reproduction by spherical conidia formed in chains by 

 transverse fission of cells; conidia formation acropetal, limited to short branches of 

 the younger portion of the filaments. 



The type species is Clonothrix fusca Roze. 



1. Clonothrix fusca Roze. (Roze, 

 Jour. d. Bot., 10, 1896, 325; Clonothrix 

 fusca Schorler, Cent. f. Bakt., II Abt., 

 12, 1904, 689; Crenothrix fusca Dorff, Die 

 Eisenorganismen, Pflanzenforschung, 

 Heft 16, 1934, 41.) From Latin fuscus, 

 brown. 



Cells cylindrical with rounded ends, 

 2 by 10 microns, becoming larger toward 

 the base and smaller toward the tips of 

 the filaments. 



Sheaths 7 microns at the ba.se to 2 mi- 

 crons at the tips. 



Conidia about 2 microns in diameter. 



This organism was described by Roze 

 as a blue-green alga, but subsequent 

 observers have failed to find pigment. 

 It was described independently by 

 Schorler who gave it the same name. 

 Cholodnj' considered it identical with 

 Crenothrix polyspora but Kolk (Amer. 



Jour. Bot., 25, 1938, 11) has clearly 

 differentiated these species. 



Habitat: Waterworks and pipes. 



Appendix: .Vpparentlj' the following 

 species resemble Clonothrix fusca: 



Clonothrix tenuis Kolkwitz. (Kolk- 

 witz, Schizomycetes in Jvryptogamen- 

 flora der Mark Brandenburg, S, 1915, 

 144; Crenothrix temns Dorff, Die Eisen- 

 organismen, Pflanzenforschung, Heft 

 16, 1934, 42.) From the settling basin 

 of a sewage plant near Berlin. Dorff 

 thinks this may have been a growth form 

 of Crenothrix fusca Dorff. 



Mycothrix abundans Xaumann. 

 (Kungl. Svenska Vetenskapsakad. 

 Handl. I, 62, 1921, Part 4, 44.) From 

 the Aneboda region, Sweden. The type 

 species of the genus Mycothrix. 



Mycothrix clonotricoides Xaumann 

 (loc. cit., 54) . From the Aneboda region, 

 Sweden . 



Genus III. Leptothrix Kiitzing. 



(Kiitzing, Phycologia Generalis, 1843, 198; not Lcptotrichia Trevisan, Reale 1st. 

 Lombardo di Sci. e Lettere, Ser. 2, 12, 1879, 138; Detoniella DeToni and Trevisan, in 



