FAMILY VI. SIDEROCAPSACEAE 217 



at right angles to the axis of the broad, lobe- Source: Found in the aquarium in the 



like stalk. Cells 2 by 6 to 12 microns, con- 

 taining a number of highly refractile glob- 

 ules of fat or sulfur. Multiplication by 



Botanical Garden, St. Petersburg. Similar 

 but smaller organisms found b}' Henrici 



binary fission. and Johnson (Jour. Bact., SO, 1935, 63) in a 



Not cultivated on artificial media. 



Note: Nevskia pediculata Henrici and 

 Johnson is now regarded as a Lactobacillus. 

 See Lactobacillis brevis Bergey et al., syn. apolis. 

 Betabacterium vermijonne IMayer. Habitat : Found in water 



jar of water from the lily pond of the Univer- 

 sity of Minnesota greenhouse in Minne- 



FAJVIILY VI. SIDEROCAPSACEAE PRIBRAM, 1929.* 



(Tribe Siderocapseae Buchanan, Jour. Bact., 3, 1915, 615; Pribram, Jour. 

 Bact., 18, 1929, 377.) 



Si. de.ro. cap. sa'ce.ae. M.L. fem.n. Siderocapsa type genus of the family; -aceae suffix to 

 denote a family; M.L. fem.pl.n. Siderocapsaceae the Siderocapsa family. 



Cells spherical, ellipsoidal or bacilliform. Frequently embedded in a thick, mucilaginous 

 capsule in which iron or manganese compounds may be deposited. Motile stages, where 

 known, are polar flagellate. Free-living in surface films or attached to the surface of sub- 

 merged objects. Form deposits of iron and manganese compounds. Autotrophic, faculta- 

 tively autotrophic and heterotrophic species are included in the family. Found in fresh wa- 

 ter. 



The morphology of the bacteria of this family is best determined after dissolving the 

 iron or manganese compounds with weak acids and staining with Schiff's reagent. 



The type genus is Siderocapsa Molisch. 



Key to the genera of family Siderocapsaceae. 



I. Cells surrounded by capsular matter with iron compounds deposited either on the sur- 

 face or throughout the capsular material. 



A. Cells coccoid. 



1. Cells in masses in a common capsule. 



Genus I. Siderocapsa, p*. 218. 



2. Cells always in pairs in a gelatinous capsule. 



Genus II. Siderosphaera, p. 220. 



B. Cells ellipsoidal to bacilliform. 



1. Cells heavily encapsulated but do not possess a torus. f 

 a. Cells in chains in a gelatinous capsule. 



b. Chains of ellipsoidal cells embedded in a gelatinous capsule, the outlines 

 of which follow the form of the cells. 



Genus III. Sideronema, p. 220. 

 bb. Rods in pairs or chains in surface films. 



* Manuscript prepared by Prof. Robert S. Breed, Cornell Universitj^, Geneva, New York, 

 December, 1953; further revision with the introduction of additional genera and species 

 by Prof. Dr. Herbert Beger, Institutfur Wasser-, Boden- und Lufthygiene, Berlin-Dahlem, 

 Germanj% March, 1954. 



t The so-called torus is a marginal thickening of a thin capsule. The torus is heavily im- 

 pregnated with iron compounds so that the torus of an individual cell looks like the link 

 of a chain or, if incomplete, like a horseshoe. 



