Page:Bergey's manual of determinative bacteriology.djvu/240




 * aa. Coccoid to rod-shaped cells in masses in a gelatinous capsule. Usually show an irregular arrangement of cells.


 * 2. Cells with a thin capsule with a torus.


 * a. Torus completely surrounds the cells.


 * aa. Torus open at one pole giving the wall the appearance of a horseshoe.

II. Non-encapsulated cells which form deposits of iron compounds in the cell wall, on the surface of the cells or in the surrounding medium.


 * A. Cells coccoid.


 * B. Cells rod-shaped.


 * 1. Found in neutral or alkaline waters.


 * 2. Found in acid mine wastes.

Si.de.ro.cap'sa. Gr. noun siderus iron; L. noun capsa a box; M.L. fem.n. Siderocapsa iron box.

One to many spherical to ellipsoidal, small cells embedded without definite arrangement in a primary capsule. The primary capsules may be surrounded by a large secondary capsule, and these may then be united into larger colonies. Iron compounds are predominantly stored on the surface of the primary capsule, and when a secondary capsule is present, it is also completely covered.

The type species is Siderocapsa treubii Molisch.

I. Several cells in each capsule.


 * A. Attached forms.


 * 1. Cells small; up to 8 in number in each capsule.


 * 2. Cells larger; up to 100 and more in each capsule.


 * B. Plankton forms.


 * 1. Primary capsules 3.5 to 9 microns in diameter, each containing 2 to 8 cells.


 * 2. Primary capsules 10 to 20 microns in diameter, each containing up to 60 or more cells.

II. Only one cell in each capsule. Cells always small.


 * A. Capsules attached.


 * B. Capsules form unattached iron floes.