Page:Bergey's manual of determinative bacteriology.djvu/296

 rounding the trichomes are very thin, delicate, colorless sheaths which do not store iron or manganese compounds. The cells are small and disc-shaped and are uniform in size. Conidia of the same diameter as the cells are produced. Found in salt water.

Hansgirg (Bot. Ztg., 49, 1891, 313) concluded that Phragmidiothrix should be included in the genus Crenothrix, and that the genus Crenothrix should be divided into two sections, Eucrenothrix and Phragmidiothrix.

The type species is Phragmidiothrix viuUise'ptata (Engler) Engler.

1. Phragmidiothrix multiseptata (Engler, 1882) Engler, 1883. (Beggiatoa jnultisepiata Engler, Verhandl. bot. Ver. Brandenburg, U, 1882, 19; Engler, Vierter Ber. d. Commission z. wissensch. Unters. d. deutsch. Meere in Kiel fur 1877 bis 1881, I Abt., 1883, 187; also see Zopf, Die Spaltpilze, 1883, 104.) mul.ti.sep.ta'ta. L. mas.n. multus much; L. adj. septatus fenced; M.L. adj. multisep- tatus much-fenced, with many septa. Colorless trichomes, several millimeters long, which form grayish white tufts. The trichomes are sessile; when young they are 1.5 microns wide, but when older they meas- ure 2 to 3 microns at their bases and 5 to 6 microns at their tips. Very thin, delicate sheaths which are not encrusted with iron or manganese oxides surround the tri- chomes. The cells are disc-shaped, their width being 1.5 to 4.0 microns while their length is only }4: to l^ this size. Each cell has a very thin, colorless membrane and some hyaline granules. When mature, the cells in the upper por- tion of the trichomes divide longitudinally and transversely and form uniformly sized conidia (1 micron in diameter). These co- nidia may be extruded, may become free by decomposition of the sheath, or they may germinate within the sheath. The extruded conidia may produce zoogloeal masses be- fore they germinate. Source: From the body of a crustacean (Gammarus locusta) from sea water; also found on seaweeds in polluted water on the shores of the northern Adriatic. Habitat : Found in polluted salt water.

Clo'no.thrix. Gr. noun clon, clonis twig, slip; Gr. noun thrix, trichis hair; M.L. fem.n. Clonothrix twig hair.

Attached trichomes 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 portions of the trichomes.

The type species is Clonothrix putealis (Kirchner) Beger.

1. Clonothrix putealis (Kirchner, 1878) Beger, 1953. {Glaucothrix putealis Kirchner, Kryptogamen-Flora von Schlesien, 2, 1, 1878, 229; Clonothrix fusca Roze, Jour, de Botanic, 10, 1896, 325; Beger, in Beger and Bringmann, Zent. f. Bakt., II Abt., 107, 1953, 327.) pu.te.a'lis. L. adj. putealis belonging to a well. Ensheathed trichomes, up to 0.6 mm long, which show false branching and which taper towards the tip; the bases of the trichomes measure 7 microns and the tips measure 2 microns in diameter. The sheaths may be- come encrusted with oxides of manganese and/or iron, particularly those of manga- nese. Sheath encrustations may reach a thickness of 24 microns when manganese oxides are prevalent and 10 microns when iron oxides are abundant. Cells cj'lindrical with rounded ends, 2 by 10 microns, be- coming larger toward the base and smaller toward the tips of the trichomes. Multiplication by extrusion of single cells