THE CLASSIFICATION OF BACTERIA 371 



4. Leptothrix gigantea Miller 



Ber. deutsche bot. Gesellsch., 1883, Heft 5. 



Occurs as tufts of filaments of considerable length and of variable thickness, 

 either straight, irregular, or spirally bent ; composed of long and short 

 rods and cocci. In a certain stage a sheath is observed, from which the 

 rods and coccoid forms escape. 



Habitat. In mucus from human teeth. 



5. Leptothrix innominata Miller 



Die Bakt. der Mundhohle, II Auf., Berlin, 1894. 



Leptothrix buccalis (?) Robin: Histoire Naturelle des Vegetaux parasites, 1853. 



Filaments 0.5-0.8 //. in diameter, unsegmented, somewhat undulate. Stain a 



faint yellow with iodine. Not cultivated. 

 Jiabitat. From the teeth of man. 



6. Leptothrix buccalis Miller 



Leptothrix buccalis-maximus Miller: I.e. 



Filaments 1-1.3 : 3~ 1 S Pi occur singly, or in parallel bundles. Stain brown 

 violet with iodine, and composed of segmented rods. Not cultivated. 

 Habitat. From the teeth of man. 



PHRAGMIDIOTHRIX Engler 



Bot. Verein der Provinz Brandenburg, 1882, 19. 



Filaments with a very delicate sheath, only visible in old filaments. The 

 filaments consist at first of groups of cells in one plane, which later divide 

 in three directions of space, forming Sarcina-like packets. Later, the 

 single cells assume a spherical form, and become free. 



i. Phragmidiothrix multiseptata Engler 



Filaments 3-12 /x broad by 100 /x long. Found attached to the bodies of 

 crustaceae, Gammarus locust a. 



