428 GENERAL SYSTEMATIC BACTERIOLOGY 



It is possible that Plectridium is not sufficiently distinct to require 

 recognition separate generically from Clostridium. It is made a 

 synonym of Clostridium by Winslow et al. (Committee Soc. Am. Bact., 

 1917, and 1920) and by Bergey et al. (1923). 



Plectrillum. A generic name proposed by Fischer (1895, p. 144) 

 for rods motile by means of a tuft of polar flagella, and with spores 

 terminal and causing enlargement of the rod (Drumstick shapes). 

 No species were named. 



Plectrinium. A genus of rod shaped bacteria named by Fischer 

 (1895, p. 142) with the following definition: 



Plectrinium nov. gen. Beweglich mit polarer Einzelgeissel, Endosporen in 

 einem aufgeschwoUenen Ende. Auch fur diese Gattung fehlt es vorlaufig noch 

 an einem sicheren Beispiel. Zopf bildet zwar eine Kopfchenbakterie mit einer 

 Geissel am nicht geschwoUenen Ende ab, giebt aber weder den Fundort noch 

 sonst etwas an. 



No species was named. The genus is apparently invaUd. 



Plennobacterium. A spelling of Plennohakterium (q.v.) used by 

 Kossowicz and others. 



Plennobakterium. Gonnermann (1907, p. 887) named an organism 

 belonging to the hay bacillus group Plennohakterium. It is non- 

 motile and gram positive, forms spores and liquefies gelatin. The 

 rods are 0.4 to 0.6 wide, 2.5 to d.O/j. long. Sometimes in filaments. 

 Characteristic spiral bands were observed within the cell. It was 

 isolated from sugar beet sap. 



No species is named. It may be regarded as a casual designation 

 iind not entitled to generic standing. 



The name is spelled Plennobacterium by certain authors as Kosso- 

 wicz. 



Pleurococcus. A genus of algae named by Meneghini (1842) to 

 which certain bacteria have been assigned as Pleurococcus Beigelii 

 Rabenhorst 1867 which became Hyalococcus heigelii Schroter and 

 Micrococcus beigelii Migula, and Pleurococcus roseo-persicinus Raben- 

 horst which became Lamprocystis roseo-persicinus Migula. 



Pleurospora. A subgenus of the bacterial genus Cornilia used by 

 De Toni and Trevisan (1889, p. 1002) with the description: "Sporae 

 macrosomae e latere protuberantes^' to contain two species, Cornilia 

 tremula and C. sphinx. The name has apparently not been used by 

 other authors. 



