5. Thiothrix longiarticulata Klas, 1936. (Arch. f. Protistenk., 88, 1936, 126.) lon.gi.ar.ti.cu.la'ta. L. adj. longus long; L. part. adj. articulatus jointed; M.L. adj. longiarticulatus long-jointed. Trichomes, 3.3 to 6.6, most frequently 4.2, microns in diameter, of uniform width, occurring in dense, felted masses. The seg- ments are long, measuring 19 to 33, mostly 26, microns in length. Motile segments not 3^et reported. Sulfur droplets usually ab- sent in the proximity of cross-walls. Source: Described only once from the effluent of sulfur springs at the seashore near Split, Yugoslavia. Habitat: Found in marine environments containing hj^drogen sulfide. 6. Thiothrix anulata Molisch, 1912. {Thiothrix annulata (sic) Molisch, Cent. f. Bakt., II Abt., S3, 1912, 58.) a.nu.la'ta. L. adj. anulatus furnished with a ring. Trichomes 3 to 4, occasionally up to 5, microns in diameter, being thinner at the base (2 microns) and at the tip (1.8 mi- crons). The trichomes are very long and may reach a length of 5 mm or even longer; they are found attached to detritus in the sea water. The segments are only about 1 micron in length. The included sulfur gran- ules are very small and numerous; in old trichomes the granules become so massed that they are no longer recognizable as dis- tinct granules. Narrow bands which are free of sulfur are often found, thus giving a ringed appearance to the trichomes. Old trichomes may show special thickening and distortion, but this is not characteristic of the species. Source: Described as white, floating specks in a glass jar containing sea water in which algae were rotting; the water was obtained from the harbor at Trieste. Habitat: Found in sea water containing hydrogen sulfide and decomposing organic matter (algae). 7. Thiothrix marina Molisch, 1912. (Cent. f. Bakt., II Abt., 33, 1912, 58.) ma.ri'na. L. adj. marinus marine. The trichomes, about 1.0 (0.8 to 1.3) mi- cron in diameter and of uniform width, are relatively slender and short in comparison with those of Thiothrix anulata Molisch; they measure from 130 to 300, rarely as much as 500, microns in length. Comment: This may be the form of Thio- thrix tenuis reported by Bavendamm (Die farblosen und roten Schwelfelbacterien, Pflanzenforschung, Heft 2, 1924, 107) as found in sea water. Source: Found in a deep, cylindrical, glass vessel in which the aquatic phanero- gam Zostera sp. was rotting. From the har- bor at Trieste. The threads formed a felted film over the surface. Habitat: Found in sea water containing hydrogen sulfide and decomposing organic matter. FAMILY II. VITREOSCILLACEAE PRINGSHEIM, 1949.* (Pringsheim, Bact. Rev., 13, 1949, 70; also see Jour. Gen. Microbiol., 9, 1951, 124.) Vit.re.os.cil.la'ce.ae. M.L. fem.n. Vitreoscilla type genus of the family; -aceae ending to denote a family; M.L. fem.pl. n. Vitreoscillaceae the Vitreoscilla family. Cells occur in colorless trichomes of varying degrees of flexibility. The trichomes show a gliding motion when in contact with a substrate, the speed of movement varying inversely with the width of the trichome. One end of a trichome may become attached to a surface, the other end then becoming free-swinging. Gram-negative. The gliding habit determines the nature of growth: on agar low in nutrients, wavy, curly or spiral colonies are produced;
- Prepared by Mr. Erwin F. Lessel, Jr., Cornell University, Geneva, New York. Re-
viewed by Prof. E. G. Pringsheim, Pflanzenphysiologisches Institut, Gottingen, Deutsch- land, October, 1955.
