FAMILY VI. SIDEROCAPSACEAE 



219 



1. Siderocapsa treiibii Molisch, 1909. 



{Siderocapsa Treuhii (sic) Molisch, Ann. 

 Jard. Bot. Buitenzorg, 2 Ser., Supp. 3, 1909, 

 29; also see Die Eisenbakterien, Jena, 1910, 

 11.) 



treu'bi.i. M.L. gen. noun treuhii of Treub; 

 named for Prof. Treub, director of the 

 Tropical Garden at Buitenzorg, Java. 



Cocci, 0.4 to 0.6 micron in diameter. As 

 many as 8 cells may be embedded in zoo- 

 gloeal masses surrounded by ferric hy- 

 droxide and other iron or manganese com- 

 pounds; these masses are 1.8 to 3.6 microns 

 in diameter. 



Deposits ferric hydro.xide on the surfaces 

 of water plants. 



Regarded by Hardman and Henrici (Jour. 

 Bact., 37, 1939, 97) as a heterotrophic organ- 

 ism that utilizes the organic radicle of 

 organic iron compounds, depositing the iron 

 as a waste product on the capsules of the 

 colonies. 



Source: Found attached to the roots, root 

 hairs and leaves of water plants {Elodea, 

 Nymphaea, Sagittaria, Salvinia, etc.) in Java. 



Habitat: Widely distributed in fresh 

 water. Epiphytic on submerged plants or 

 on other objects. Abundant in alkaline, 

 hard-water lakes of the drainage type in 

 Minnesota and Wisconsin according to 

 Hardman and Henrici {ibid., 103). Absent 

 in neutral or acid soft-water lakes of the 

 seepage type. 



2. Siderocapsa major Molisch, 1909. 

 (Ann. Jard. Bot. Buitenzorg, 2 S^r., Supp. 

 3, 1909, 29; also see Die Eisenbakterien, 

 Jena, 1910, 13.) 



ma'jor. L. comp.adj. major larger. 



Cells colorless, coccus-like, short rods, 

 0.7 by 1.8 microns. A colony may consist of 

 100 or more cells in the same mucilaginous 

 capsule. 



Similar to Siderocapsa treuhii except that 

 the cells are larger and the gelatinous 

 capsule is less sharply defined. May be free- 

 floating in surface films or may be attached 

 to submerged objects. 



Forms intermediate between Siderocapsa 

 major and Siderocapsa treuhii have been 

 observed by Hardman and Henrici (Jour. 

 Bact., 37, 1939, 97). 



Source: Found on the surface of a Spiro- 

 gyra sp. near Prague. 



Habitat: Widely distributed in fresh 

 water. 



3. Siderocap.sa coronata Redinger, 1931. 

 (Arch. f. Hydrobiol., ££, 1931, 410.) 



co.ro.na'ta. L. part. adj. coronatus 

 crowned. 



Coccoid cells, about 1.0 micron in diam- 

 eter, occurring in the primary capsule in 

 groups of 2 to 8. These groups are sur- 

 rounded by secondary gelatinous capsules 

 which may unite into foamy, irregular 

 masses 5 to 10 or more cm in diameter. The 

 capsular material contains deposits of iron 

 and manganese. Free-floating. Yellowish to 

 dark brown in color. 



Source: Found in water from Upper 

 Lake, Lunz, Austria. Foamy masses are 

 formed in the winter time. Ruttner (Arch, 

 f. Hydrobiol., 33, 1937, 167) reports that the 

 distribution of this organism in Alpine lakes 

 is related to the o.xygen stratification 

 therein : it was found most frequently at 

 depths of from 17.5 to 27.5 meters, where the 

 oxygen range was 0.12 to 0.30 mg per liter. 

 4.66 mg per liter was the highest oxygen 

 tension at which it was found. 



Habitat: Presumably widely distributed 

 in water. 



4. Siderocapsa eusphaera Skuja, 1948. 

 (Symbolae Bot. Upsal., 9 (3), 1948, 12.) 



eu.sphae'ra. Gr. prep, eu true; Gr. noun 

 sphaera ball, sphere; M.L. noun eusphaera 

 a true sphere. 



Cells coccus-shaped, 1 to 2 microns in 

 diameter, 2 to 60 and more in a primary 

 capsule. The latter are 10 to 20 microns in 

 diameter and are surrounded by a large 

 secondary capsule up to 50 microns in diam- 

 eter. The secondary capsules are united into 

 large colonies with a common mucilaginous 

 layer. The secondary capsule stores com- 

 pounds of iron and manganese. 



Source: Found in lakes in Sweden; found 

 in the plankton at levels where the oxygen 

 tension is low. 



Habitat: Presumably widely distributed 

 in fresh-water lakes. 



