1921] NATURAL SCIENCES OF PHILADELPHIA. 133 



the opinion that the genus Chrysamoeba is in fact a purely amoeba- 

 like form, with never any flagella, comparable to those of organisms 

 like Chromulina or even Ochromonas, but owing to this very absence 

 of flagella, these forms are so characteristic in themselves that it 

 seems advisable to retain Chrysamoeba as representing an inde- 

 pendent genus." 



Pascher, in the fascicle of his " Slisswasser-Flora" (27), which 

 treats of the Chrysomonadina and is dated 1913, does not even 

 mention the name Chrysamoeba in his list of accepted genera but 

 only devotes a few lines to the subject, in a foot-note on page 13: 

 "Klebs has created the name Chrysamoeba for Chromulina-Wke 

 Chrysomonadina with two large chromatophores and an anterior 

 contractile vesicle, which may turn into Rhizopods and develop 

 pseudopodia after losing their flagella." In the same work, on 

 page 90, Pascher comes again to the subject, and considers this 

 same organism as belonging to the genus Rhizochrysis, "an arti- 

 ficially created genus that includes several Chrysomonadina of differ- 

 ent origin, whose Flagellate-stage has been lost or in which, if pres- 

 ent, it is not yet known." Chrysamoeba^ such as Scherffel under- 

 stood it, has now become Rhizochrysis scherffeUi Pascher.^" 



During these last four years, while looking for Infusoria, 

 I have often met with Chrysamoeba, in several localities and in all 

 seasons of the year, and at the end of 1914 and the beginning of 

 1915, I devoted some time to its study (perhaps it is not quite use- 

 less to state that most of my collections of material were made 

 after breaking a thick layer of ice), and was able to come to some 

 interesting conclusions. The Uttle organism I had to do with was, 

 I must say, at the same time, Chrysamoeba radians Klebs, Rhizo- 

 chrysis scherffeUi Pascher, and also the Chrysamoeba-like Chj-omu- 

 lina Scherffel speaks of. In my opinion, one single organism i? 

 here concerned, Chrysamoeba radians Klebs, a verj^ distinct and 

 characteristic species and genus. 



Let us first insist on the fact that Chrysamoeba is a colonial or- 

 ganism. Scherffel, in 1908, sometimes found "large colonies of 

 Chrysamoeba-\\kQ amoebae, where more than a hundred typical 

 and well-developed specimens, all without any flagellum, were in- 

 cluded in an amorphous, free-swimming jelly." At Pinchat, these 

 colonies were very abundant, sometimes very much reduced and 



1° According to Pascher, the Chrysamoeba which Scherffel observed is not the 

 same as that described by Klebs. 



