1916] Wilson: On the Life-Histonj of a i^oil Amocha 275 



in this paper are probably all the same species. Nacgleria gntberi 

 (Schardinger). 



Attention should be called to Alexeieff's (1912f/) classification of 

 this species. He calls it Dimastigamoeba gruheri (Schardinger. 1899). 



Siinonyms: 



Amoeba gruberi Schardinger, 1890. 



A. punctata Dangeard, 1910. 



A. punctata Dangeard, Alexeieif, 1911. 



Valiliampfia punctata (Dangeard) Chatton et Lahimb-Boiinaire 1912. 

 Nacgleria punctata (Dangeard) Alexeieff, 1912 c. 



It should be noted in this connection that Amoeba gruberi agrees 

 with Naegleria punctata (Alexeieff, 1912c) in every respect so far as 

 described, except in the character of the cyst wall, which is of even 

 thickness in the first-named species and not as Alexeieff (1912c) has 

 figured it in Naegleria 'punctata. All the cy.sts examined by me in 

 Naegleria. gruberi have walls of even thickness. In this species also 

 the rhizoplast is found connecting the karyosome and blepharoplast, 

 and not nuclear membrane and blepharoplast as figured in Naegleria 

 punctata. 



Alexeieff .says that there is a complete resemblance between VaJil- 

 kampfia punctata and Dimastigamoeba radiata Bloehmann (1895). If 

 this resemblance proves valid, then Dimastigamoeba will have to be 

 used instead of Naegleria for bifiagellated amoebas. 



Should Dimastigamoeba be used for the generic name of the bi- 

 fiagellate amoebas, they would be placed in a genus in which the other 

 species are fiagellated throughout their free state in so far as is now 

 known, while in these forms a flagellate condition is occasional and 

 temporary. The return to the flagellate state is perhaps not of long 

 enough duration and frequent enough, .so far as is apparent, to be 

 considered an adult characteristic, the evidence seeming to indicate 

 that it is for distributional purposes only, and for this reason that 

 name should not be used for this species. The genus was created for 

 two amoeboid flagellates, and unless these have a non-flagellated amoeba 

 .stage, Naegleria should be retained as the generic name for the bi- 

 fiagellated amoebas, which seem more closely related to the Rhizopoda 

 than to the Alastigophora. 



