THE MYXOBACTERIALES AND SPIROCHAETALES 543 



Family I. Spirochaetaceae Swellengrebel 1907, p. 581 



Synonyms : 



Spirochaetoidea Dobell, 1911, p. 536 

 Spironemaceae Gross, 1912, p. 83 ' 



Characters those of the order. 



The following generic names have been used for organisms of 

 this group: 



Spirochaeta Ehrenberg, 1833, p. 313. 

 Spirochoeta Dujardin, 1841, p. 209 

 Spirochaete Cohn, 1872, p. 180 

 Treponema Schaudinn, 1905, p. 1728 

 Miscrospironema Stiles & Pfender 1905, p. 936 

 Spironema Vuillemin, 1905, p. 1567 

 Borrelia Swellengrebel, 1907, p. 582 

 Cristispira Gross, 1910, p. 41 

 Saprospira Gross, 1911, p. 188 

 Spiroschaudinnia Sambon, 1913, p. 833. 

 The genera recognized may be differentiated by use of the 

 following key: 



Key to the genera of Spirochaetaceae 



I. Usually saprophytic, free living in water. 



A. Protoplasm spirally wound around an elastic axis filament. 



Genus I. Spirochaeta 



B. Not as in (A), cross section circular Genus II. Saprospira 



II. Usually parasitic. 



A. Possessing a "crest" or ridge. Parasitic in mussels. 



Genus III. Cristispira 



B. Without a crest. Parasitic in warm blooded animals. 



Genus IV. Treponema 



Genus I. Spirochaeta Ehrenberg, 1833, p. 313 



Synonyms : 



Spirochaete Cohn, 1872, p. 180 

 Spirochoeta Dujardin, 1841, p. 209 

 Slender, spiral cells, living free, usually in water containing hy- 

 drogen sulphide, actively motile, flexuous. Flagella unknown. An- 

 aerobic. Protoplasm is spirally wound around a flexible or elastic 



