RECENT MEMOIRS ON rUESHWATER RHIZOPODA. 199 



a globular form, becomes covered by a thick membrane. 

 The finely granular contents of the cysts, generally lying in 

 clusters, becomes so dark that no insight can be gained of 

 their histological nature. Schneider described a fourfold 

 division of the contents, which Cienkowski was unable to 

 confirm. 



Platoum parvum, Eilh. Schulzei (fig. 4), 



is the name given by that author to a marine form, which 

 again he makes the type of a new genus and species. How- 

 ever opinions may differ as to the propriety of relegating the 

 preceding form {Chlamidophrys stercorea, Cienk.) to the 

 older genus Plagiophrys, there seems, at any rate, no doubt 

 but this form and the preceding at least are congeneric, in 

 which case the name Platoum would have the priority. In 

 the present form the Euglyphan body-mass is suspended 

 ■within a structureless hyaline membranous test, the latter 

 differing in its form from that of Cienkowski's C stercorea. 

 The author regarded it, as it were, intermediate between 

 Cyphoderia and Gromia, but the former is wide apart by 

 reason of its areolated test, whilst the forms referred by this 

 author to the latter genus seem mainly to belong truly to 

 Plagiophrys, from which this and the preceding form seem 

 to differ only as pointed out. 



The form is compressed, in the broader view it is ovate, 

 often a little curved, one front arched or convex, the other 

 flat or a little convex ; the aperture of the test is round, its 

 border a little thickened. The body-mass with its posterior 

 nucleolated nucleus, middle granular zone, and anterior hya- 

 line region, often with one or two pulsating vacuoles and 

 long, slender, very slightly branched, non-granuliferous pseu- 

 dopodia (fig. 4) ; all are quite like those of Cyphoderia or 

 Euglypha, but the structureless, simply membraneous test 

 separates it from these genera (if they, i. e., Cyphoderia and 

 Euglypha, indeed, should ultimately be maintained as dis- 

 tinct). 



Its test is in that respect similar to that in Hyalo- 

 sphenia (Stein); but the Euglyphan, that is to say, fila- 

 mentary, slightly branched, and more or less tufted (not 

 Difflugian, that is, lobose) character of the pseudopodia 

 completely separates it therefrom. 



And the reference to Hyalosphenia causes a momentary 

 retrogression in order to seize the opportunity here to 

 apologise to Mr. Tatem for my having overlooked that 



1 Loc. cit., Bd. xi, p. 115, t. vi, f. 1-4. 



