21 



dense shrub-like tuft of more or less branched, linear, pseu- 

 dopodia of quite the same character as that of those belonging 

 to the forms drawn attention to above in the preceding section. 

 One of these tufts is always notably larger and more drawn 

 out than the other. It sometimes happens that one of the 

 apertures becomes stuiFed up by foreign granular particles 

 clustered in a heap, so mucli so as seemingly to prevent the 

 emission of any pseudopodia at all, or only a few straggling 

 ones make their way out from amongst the particles. Indeed, 

 it is quite rare to g^t examples in which the short neck-like 

 margin of the aperture can be seen in either, not to speak of 

 both ends, for the same kind of foreign particles which abound 

 at the margin have a tendency to be retained around the 

 aperture, obscuring its margin, and rendering it hard to be 

 proven that a neck-like border exists. The body assumes 

 generally a narrower form than the test, thus usually leaving 

 a space at each side, though it sometimes appears to com- 

 pletely fill the test. It is always densely loaded with chloro- 

 phyll granules, along with which occur other brownish 

 coloured particles. I have not seen a nucleus, nor have I 

 seen crude food in its interior. 



This seems a sufficiently remarkable form, inasmuch as 1 

 do not know of the existence of another rhizopod of its affinity 

 with a single chamber, and with two large apertures for the 

 emission of pseudopodia, if we except Diplop/wys Ai'cheri 

 (Barker) .1 To the seeming distinctions of these two forms 

 in a generic point of view I shall allude below ; in an indi- 

 vidual or specific point of view no two forms could be more 

 distinct, though the descriptions of each to a certain extent, 

 no doubt, coincide. 



Having thus, in the foregoing sections of this communica- 

 tion, passed in review the various new Rhizopoda figured on 

 the present occasion (with the exception of Dlffiuyia cari- 

 nata), the account of the forms described must naturally 

 conclude with their short diagnostic, generic, and specific 

 characters. 



However, as regards locating them first in their due position 

 in higher, more comprehensive groups, it docs not appear to 

 me that the known forms of Khizopoda inhabiting the fresh- 

 waters are yet sufficiently numerous or sufficiently under- 

 stood to enable us to classify them otherwise than approxi- 



1 'Quavf. Jour. Mic. Sci.,' vol. xvi, p. 123, in " ProceeJiiigs of Dublin 

 Microscopical Club," I9tb December, 1867. 



