402 GENERAL SYSTEMATIC BACTERIOLOGY 



Apparently the correct type designation would be Nitrosococcus 

 nitrosus (Migula). 



Winslow et al. (Committee Soc. Am. Bact. (1917, 1920)) merged 

 this genus with Nitrosomonas, q.v. 



Nitrosomonas. A generic name proposed by Winogradsky (1892, 

 p. 127) to replace the earlier Nitromonas. He says 



Les ferments nitreux du vieux monde ferarent partie du genre Nitrosomonas 

 (au lieu de Nitromonas, que j'ai propose avant) avec duex especes: Nitrosomonas 

 europaea, Nitrosomonas javanensis (d'autres encore, peut etre) et des varietes 

 locales. 



The organisms oxidize ammonia to nitrites. They are rod-shaped 

 forms, being differentiated in this respect from the new world genus 

 Nitrosococcus. 



Migula (1900, p. 954) included this genus in his genus Pseudomonas. 

 The name was rejected by Erwin F. Smith (1905, p. 162). Orla- 

 Jensen (1909, p. 334) includes this as the fifth genus of his family 

 Oxydobacteriaceae. 



Winslow et al. (1917, p. 552) included Nitrosococcus in this genus, 

 and used the following diagnosis. 



Cells rod-shaped or spherical, motile or non-motile, if motile with polar fiagella. 

 Capable of securing growth energy by the oxidation of ammonia to nitrites. 

 Growth on media containing organic substances scanty or absent. 



The type species is Nitrosomonas europoea Winogradsky. 



Buchanan (1918, p. 180) gave the following generic description. 



Cells rod-shaped. Motile. Not growing readily on organic media. Oxidizing 

 ammonia to nitrates. 



The type species is Nitrosomonas europoea Winogradsky. 



Bergey et al. (1923, p. 35) followed the Committee, including this 

 as the fourth genus of the tribe Nitrohactereae. 



Nocardia. A generic name proposed by Trevisan (1889, p. 9) to 

 create a vaUd name to replace the invaUd terms Streptothrix Cohn, 

 Actinomyces Harz and Discomyces Rivolta. It is included as the third 

 genus of the tribe Cladotrichee . The generic description given is 

 "Cladothrix senza vagine." Five species are listed, N.farcinica and 

 N. actinomyces being the first two. The generic description given 

 by De Toni and Trevisan (1889, p. 927) is as follows: 



Filamenta tenuissima, evaginata, articulata, Cladotricis more pseudoramosa, 

 nunc e nucleo firmo radialiter expansa, nunc varie coalita. Arthrosporae in 



