Page:Bergey's manual of determinative bacteriology.djvu/245

 Slender rods measuring 0.5 by 2.5 microns. Rods, several to many placed irregularly in a gelatinous envelope, form, when old, zoogloea-like masses as much as 7.5 microns in diameter. The rods are surrounded by primary capsules which are impregnated with iron compounds and which later fuse. Reported by Dorff (Tabulae Biologicae, 16, 1938, 221) to be autotrophic. Comment: The characters of the genus Siderocystis, as described by Naumann {loc. cit.), do not seem adequate to distin- guish it from the genus Sideromonas, estab- lished earlier by Cholodny. Source: Found in the Aneboda region in Sweden. Habitat: Forms deposits on submerged objects in ditch and river waters.

4. Sideromonas major (Naumann, 1922) Beger, comb. nov. {Siderothece major Nau- mann, Kungl. Svenska Vetenskapsakad. Handl., 62, No. 4, 1922, 17; Siderothece minor Naumann, loc. cit.; Siderocystis minor Naumann, ibid., 43.) ma'jor. L. comp.adj. major larger. Rods broader than those of Sideromonas vulgaris, 0.5 to nearly 1.5 by 1.0 to 1.5 mi- crons. Each rod is surrounded by a large primary capsule; the capsules later fuse and form a gelatinous envelope in which the cells are irregularly arranged. Form zoogloea-like masses up to 10 microns in diameter. Iron compounds deposited within the capsular substance. Possibly autotrophic (Dorff, Talnilae Biologicae, 16, 1938, 221). Aerobic. Comments: While there are some differ- ences in the sizes of the organisms placed by Naumann in the three different species named above, such differences may, in reality, not be significant: these differences may be due to variations in the nutritive value of the water in which each of the organisms was growing. Source: Found in the Aneboda region in Sweden. Habitat: Develop concretionary deposits (microscopic particles) on submerged ob- jects in swampy ditch and river waters; also found in wells and pipes in waterworks.

Nau.man.ni.el'la. M.L. dim. ending -ella; M.L. fem.n. Naumanniella named for Einar Naumann, a Swedish limnologist.

Cells ellipsoidal or rod-shaped with rounded ends, occurring singly or in short chains; the rods may be straight or curved and frequently are constricted in the middle. Each cell is surrounded by a small capsule and a marginal thickening (torus) heavily impregnated with iron and manganese compounds. Gelatinous capsules of the type found in Siderocapsa are absent. Cell division occurs simultaneously with constriction and separation of the torus. The species in this genus have not been cultured. Found at the surface and in or on the bottom mud of iron-bearing water.

The type species is Naumanniella neustonica Dorff.

I. Cells rod-shaped.


 * A. Cells occur singly.


 * 1. Cell diameter greater than 1.2 microns with the torus.


 * a. Cells with the torus 1.8 to 3.3 by 4.0 to 10.0 microns.


 * aa. Cells with the torus 1.2 to 1.5 by 3.1 to 3.6 microns.


 * 2. Cells 1 by 2 microns with the torus.