482 GENERAL SYSTEMATIC BACTERIOLOGY 



comprises three different sets of forms, which may be correspondingly classified 

 in three different genera: Spirochaeta, Treponema, Cristispira. These three 

 groups of organisms, whilst showing certain resemblances to one another, possess 

 no definite relations with Protozoa, Bacteria, or Cyanophyceae. The Spiro- 

 chaetoidea should therefore be regarded — for the present — as a group of Protista 

 which stands apart. 



Spirochetaceae. A variant spelling of Spirochaetaceae (q.v.) used 

 by Schneider. 



Spirochoeta. A spelling of Spirochaeta used by Dujardin (1841) 

 according to Stiles (1905) and occasionally used by medical writers. 



Spirodiscus. A generic name used by Ehrenberg (1828, p. 34) 

 as the fifth genus of the Vibrionen. One species, S. fulvus, was de- 

 scribed from a mountain stream, growing among Conferva. The 

 organism is described as forming a flat spiral. Its relationship to the 

 bacteria is very doubtful. It apparently has not been observed since 

 the first description. Ehrenberg states, "Animale e familia Vibrion- 

 iorum, divisione spontania imperfecta (et obliqua?) in catenam fili- 

 foi'men S. cochleam rigidam disciformen accrescens." 



Dujardin (1841, p. 226) regarded this as a doubtful genus. 



Perty (1852, p. 179) questioned the location or identification of this 

 genus in the following statement: 



Hier wlirde sich noch die Sippe Spirodiscus E. anschliessen, da die einzige 

 bekannte Species (Sp. fulvus E. p. 86, t. 5, f . 1) nicht etwa eine Pilzspore ist, bei 

 welchen ofters Bewegung wahrgenommen wird. 



Migula (1897, I, p. 6) states that perhaps this form belongs with 

 the sulphur spirilla, but that it is in a high degree doubtful whether it 

 should be regarded as belonging to the bacteria. The genus may be 

 regarded as of questionable value. 



Spiromonas. A genus described by Perty (1852, p. 171). The 

 organism was described as related to the spirUla, but with the cells 

 flat and band shaped. It multiplies through transverse fission. One 

 species is included, Spiromonas volubilis. 



The genus was recognized by Trevisan (1879, p. 138) with the de- 

 scription "Somatia compressa ligammiformia, valida, abbreviata, 

 spiralita torta." It was included in his subtribe Eumhrionieae. Win- 

 ter (1884, p. 62) gave the following generic description: "Zellen "blat- 

 tartig" (fiach) zusammengrdriickt, um eine ideale Achse der lange 

 nach gewunden. Vermehrung durch Quertheilung." 



