1916] Swezy: The Genera Monocereomonas atid Poliinia.tti.r 131 



Franca (1913) figures a Polymnsti.r from the larva of Oryctes 

 which presents the same characteristics as those previously described 

 by Mackinnon and Hamburger. 



It is thus evident that some clear distinctions exist between the 

 flagellates placed in the genus Polymastix by these investigators, and 

 the form from frogs and salamanders. Another feature is the presence 

 of the "siderophile" body of Alexeieff (1911), or parabasal body. 

 The homologue of this body may, however, be the extra-nuclear 

 siderophilous granules figured in the Polymastix from Tipula by 

 Mackinnon (1912). 



These distinctions do not seem to warrant the creation of a new 

 genus for the flagellate from frogs and salamanders. It is therefore 

 proposed, provisionally at least, to place it in the genus Polymastix 

 as P. bufonis (Dobell). 



Morphology op Polym.vstix Bufonis 



This flagellate is small, 10 to 15 ju, in length and 5 to 8 /t in width. 

 In outline it is more or less oval or pyriform (pi. 16, fig. 8), somewhat 

 irregular in contour but never amoeboid. The posterior end may be 

 rounded, blunt or pointed. 



The slightly thickened periplast of the body is marked by stria- 

 tions which extend obliquely across the body (text-fig. A), or in a 

 nearly longitudinal direction (pi. 16, fig. 9). There appear to be 

 thickened ridges or very slight folds in the periplast, which do not 

 show any definite staining reactions with iron haematoxylin. In many 

 specimens these striations may escape observation altogether. Some 

 time had elapsed after my first observation of this flagellate before 

 I became aware of this peculiarity in its structure. Going back over 

 my earlier material, however, I found that they could be demonstrated 

 in nearly all cases. This fact confirms my belief that the flagellate is 

 identical with the one described by Dobell (1909) and Alexeieff 

 (1911), and not a new form as might appear from the figures shown. 



The four equal flagella arise at the anterior extremity of the body, 

 usually in one group (text-fig. A) or in two groups of two flagella 

 each (pi. 16, fig. 8), though this latter case may be only an early 

 prophase of division. The flagella originate in a single granule, the 

 blepharoplast (text-fig. A, bleph.). Alexeieff (1911) figures the 

 blepharoplast as a number of minute granules. This was not found 

 to be the case in any specimens in my material. 



