RECENT MEMOIRS ON FRESHWATER RHIZOPODA. 337 



its surface glossy, its substance thick and membranous, 

 structureless. In side or edge view the test is narrow-oblong, 

 and the margins (outline of the frontal surfaces) nearly- 

 straight and parallel. The body, like that of Amphitrema 

 JVrightiamim, is loaded with chlorophyll-granules, though 

 in the few specimens only which I have seen, not so densely, 

 so as in that species, and it carries a median nucleus. The 

 pseudopodia, issuing from each pole, form a dense tuft, are 

 linear, scarcely granular or ramifying, steadily displayed, 

 and reach about one half the length of the test. They are, 

 on the whole, like those of A. Wrightianuni. As in that species 

 body does not fill the test, and indeed does not seem to be 

 in contact with it anywhere, except at the borders of each of 

 the apical openings. 



Sarcodina nuda. 

 Pelomyxa palustris (Pelobius, olim), Greeff^ (figs- 10 — 15), 

 is a very large form, a single example attaining sometimes 

 even over two millemetres in diameter. When first placed 

 on a slide its outline is generally round or but slightly 

 lobed, and of course flattened between it and the covering 

 glass. Carefully viewed, after a little pause the observer 

 sees its pellucid margin pushed oiF in wave-like lobes or 

 hemispherical and even finger-like projections, and sur- 

 rounding a dark brown body-mass (fig. 10). Here a 

 process is withdrawn, there another projected, and these 

 may even assume a filiform character arranged in tufts (some- 

 what like the villous patch of Amceba villosa). This play- 

 kept up for some time, a wave-like motion begins in the 

 interior, and abruptly at any place a broader process breaks 

 forth outwardly, into which, as into a sac, a mass of contents 

 is poured, forming a broad pseudopodium, and so the form 

 performs its locomotion, a second and third similar process 

 following thereon; thus what looked on being placed on 

 the slide like a mere little ball of mud, has now acquired a 

 much-lobed figure, as it glides with its expansive amoeboid 

 movements. 



More closely examining the contents, it is seen that the 

 dark colour and almost complete opacity are due to the pre- 

 sence of dark and opaque substances immersed in a com- 

 pletely colourless body-substance, these substances being 

 made up of all sorts of foreign bodies incepted, diatoms, 

 algse, Arcella- and Difflugia-tests, entomostraca, and above 

 all, a considerable quantity of mud and sand-particles. 

 Those examples which are the least loaded with these 

 '"■ Greeff; Schultze's ' Archiv,' Bd. x, p. 51, t. 'iii, iv, v. 



