GENERAL SYSTEMATIC BACTERIOLOGY 445 



Rhodobacteriaceae. A family of bacteria created by Migula (1900, 

 p. 1042) to include all bacteria containing bacteriopurpurin, and in 

 consequence colored rose, red or violet. They also contain sulfur 

 granules. This family is recognized by Smith (1905, p. 163), Orla- 

 Jensen (1909, p. 313), Benecke (1912), Frost (1911, p. 60) and others. 

 An ordinal name Rhodobacteria (q.v.) is used by Molisch (1907, p. 27). 



Buchanan (1918, p. 464) included this as the third family of the 

 order Thiohacteriales with two subfamilies Chromatioideae and Rhodo- 

 hacterioideae. His description is: "Cells of various types, not filamen- 

 tous, containing bacterio-purpurin with or without sulphur granules 

 also." 



Bergey et al. (1923, p. 394) included this as the first family of the 

 order Thiohacteriales. 



Rhodobacterioideae. A name given by Buchanan (1918, p. 471) 

 to the second subfamily of the Rhodobacteriaceae. The name may be 

 considered a synonym of Athiorhodaceae Molisch. The diagnosis is: 

 "Cells not filamentous, containing bacteriopurpurin but not granules 

 of sulphur." The following genera were included: Rhodocystis, 

 Rhodonostoc, Rhodosphaera, Rhodobacterium, Rhodobacillus, Rhodovibrio 

 and Rhodospirillum. 



Rhodobacteroideae. A variant spelling of Rhodobacterioideae q.v. 

 used by Bergey et al. (1923, p. 404). 



Rhodobacterium. A genus of bacteria first described by Molisch 

 (1907, p. 16) to include those bacteria containing bacteriopurpurin, 

 devoid of sulphur granules, rod shaped, and non-motile. A single 

 species, (type) Rhodobacterium capsulatum Molisch is included. 



Buchanan (1918, p. 472) included this as the fourth genus of the 

 tribe Rhodobacterioideae. Bergey et al. (1923, p. 406) followed Buch- 

 anan. 



Rhodocapsa. A genus of sulfur bacteria described by Molisch 

 (1906, p. 223). The cells contain granules of free sulfur; and are free 

 that is, not united into families, not capable of swarming. In mass 

 the organisms are rose or cherry red, due to their content of bacterio- 

 purpurin. One species was described, Rhodocapsa suspensa (the type). 



This name was also used by Orla-Jensen (1909, p. 334) as the tenth 

 genus of his family Rhodobacteriaceae. It appears that he proposes to 

 use this name to replace an older designation Thiocapsa. In this sense 

 the name would be invaHd. 



Buchanan (1918, p. 471) includes this as the fourth genus of the tribe 

 Chromatieae with the description: "Cells spherical, free (not united 



