410 GENERAL SYSTEMATIC BACTERIOLOGY 



The genus Pacinia has not been recognized by subsequent authors. 

 It is rejected by Smith (1905, p. 162) although he states that were it 

 not for the availabihty of the generic designation Vibrio for the genus 

 of which the comma bacillus is the type. Pacinia would have priority 

 over Microspira Schroeter. 



The genus is likewise rejected by Vuillemin (1913, p. 521) as not 

 satisfactorily characterized. Pacinia may probably be regarded as 

 a synonym of Vibrio. 



Pacinieae. The fifth subtribe of the tribe Bacilleae used by De 

 Toni and Trevisan (1889, p. 1015) with the following diagnosis: "Baculi 

 nudi nunquam spiraliter torti. Arthrosporae." The following genera 

 are included: Pacinia and Bacterium. 



Palmella. A genus of algae named by Lyngbye . Various bacteria 

 have been incorrectly placed here. Among them are Palmella 

 mirijica Rabenhorst = Micrococcus mirificus Trevisan, Palmella pro- 

 digiosa Montague = Micrococcus prodigiosus Cohn. 



Panhistophyton. According to Zopf (1885, p. 69) the name Pan- 

 histophyton ovatum was given by Lebert (1856) to the organism earher 

 grouped with the bacteria and now known to be a protozoon, Nosema 

 bombycis Nageli, Trevisan (1882, p. 100) says: 



La prima opinione fu emessa dal Lebert, che li ritenne un alga unicellulare, cui 

 diede il nome Panhistophyton ovatum (In Berlin. Entomolog. Zeitschr, 1858), 

 ma il Cohn avendodimostrato che erano Batteri appartenenti al genere Micro- 

 coccus, rimaseso nelle tabelle sistematische coll 'apellativo Micrococcus bombycis. 



Panhistophyton is not a bacterial genus. 



Parachromatium. An alternative to Azotobacier proposed as a 

 generic name by Beijerinck (1903, p. 217). In a footnote he says: 



Peut etre le nom de Parachromatium qui indique la parents de notre microbe 

 avec le genre Chromatium de Winogradsky, serait pr6f6rable. Des considera- 

 tions physiologiques m'avatent d'abord conduit a une tout autre opinion mais 

 des etudes ultereure me portent a croire que cette parente generique est indubi- 

 table. Zettnow, en examinant mes preparation, avait deja la meme opinion. 



The name does not seem to have been used, and may be regarded 

 as invalid as a generic designation. 



Paracloster. A generic name used by Fischer (1895, p. 141) to 

 designate those non -motile rod-shaped bacteria in which the cells 

 become spindle shaped when sporulating. The description given is 



Unbeweglich, ohne Geisseln, mit Endosporen in spindelformig aufgesch- 

 wollenen Stabchen; die Spore liegt oft genau in der Mitte, kann aber auch in 



