GENERAL SYSTEMATIC DACTERIOLOGY 255 



Saccardo (1886, p, 576) gives the following diagnosis: "Stipes ex 

 hyphis compactus, ramosus, induratus, Conidia apicalia, capitulata, 

 elongato-ovata, continua." 



The true nature of this organism was first recognized by Thaxter 

 (1892, p. 401). He designated it as one of the genera of the Myxo- 

 baderiaceae (g.v.). His diagnosis is as follows: "Rods forming free 

 cysts in which they remain unmodified. Cysts various, sessile, or 

 borne on a more or less highly developed cystophore." This genus 

 is distinguished from the related genus Polyangium Lk. in that the 

 latter forms its one or more cysts within a gelatinous matrix raised 

 about the substratum, and from the genus Myxococcus in that no 

 coccuslike spores are formed by the fruiting bodies. 



Thaxter gives the following synonomy: "Stigmatella B. and C. in 

 Berk, Introduct. Crept. Bot. p. 313. fig. 70, b. (no description). 1857, 

 do. in Grevillea 3 97. 1874 (first description). 



(?) Polycephalum Kalch and Cke. in GreviWea. 9: 22. 1880. 



(?) Cystohader Schroter in Kryptogamen Flora v. Schlesiens, Die 

 Pilze, p. 170." 



The species described by Schroter was named Cystohader eredus. 

 What is evidently a species practically or quite identical with Chon- 

 dromyces crocatus was described by Zukal (1896, p. 346) as Myxobotrys 

 variabilis (q.v.). This author also regarded it as a fungus. 



Buchanan (1918, p. 542) diagnosed the genus as follows: 



Rods forming free cysts in which they remain unmodified. Cysts various, 

 sessile or borne on a more or less highly developed cystophore. 

 The type species is Chondromyces crocatus Berkeley and Curtiss. 



This description is also used by Bergey et al. (1923, p. 416). 



Chorjmebacterium. Apparently a misprint for Corynebaderium 

 found in the index of Migula's System der Bakterien (1900, vol. 2, p. 

 1061). 



Chromatiaceae. A subfamily of sulphur bacteria created by Migula 

 (1900, p. 1047) to include three genera. Chromatium, Rhabdochroma- 

 tium and Thiospirillum. He states: "Zellen frei, zeit lebens schwarm- 

 fahig." The subfamily is characterized as containing those sulphur 

 bacteria in which the cells are free and capable of swarming at any 

 time. 



The subfamily has been generally recognized by those who have 

 discussed classification of the sulphur bacteria such as Migula (1904, p. 

 146) E. F. Smith (1905, p. 164) and Frost, (1911, p. 61). 



