STUDIES IN THE NOMENCLATURE AND CLASSIFI- 

 CATION OF THE BACTERIA 



V. SUBDIVISIONS AND GENERA OF THE SPIRILLACEAE. AND 

 NITROBACTERIACEAE 



R. E. BUCHANAN 



From the Bacteriological Laboratories, Iowa State College, Ames, Iowa 

 Received for publication October 22, 1916 



Family HI. Spirillaceae Migula, 1894, p. 237 

 Synonyms : 



Spirillina Perty, 1852, p. 179 

 Spirillineae Cohn, in ed. Rabenhorst, 1865, p. 70 

 Spirobacteria Cohn, 1872, p. 180 

 Vihrioneae Trevisan, 1879, p. 139 

 Spirobaderiaceae Hueppe, 1886, p. 143 

 Spirilleae De Toni and Trevisan, 1889, p. 1006 

 Cells elongate, not spherical, bent in the form of a spiral or a 

 segment of a spiral. Usually motile by means of polar flagella. 

 Without sulfur granules or bacteriopurpurin. 



Perty (1852) subdivided the Spirillina into the genera Spiril- 

 lum and Spirochaeta. 



Cohn (1872) Hkewise divided the tribe Spirobacteria into 

 Spirillum with cells rigid, relatively short, and Spirochaele, with 

 cells flexuous and relatively long. In 1875 Cohn described 

 the additional spiral genus Myconostoc in which the spiral cells 

 occurred embedded in a mass of gelatin, and included Vibrio, 

 Spirillum, Spirochaete and Myconostoc in the algal tribe Nema- 

 togenae. The genera may be separated by the following key. 



Key to genera of spiral Nematogenae Cohn 



A. Cells not united by gelatin into families. 



1 . Filaments short, sinuous Vibrio 



2. Filaments short, spiral, rigid Spirillum 



3. Filament long, spiral, flexible Spirochaete 



B. Cells united into a glairy family Mijconostoc 



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