Archer — On Freshwater Rhizopoda* 
101 
sent in both their species, but have been overlooked by them. When 
our form (I'ig. 11), alluded to, is treated with the carmine fluid the 
nucleus takes a deep dye (I'ig. 13), and when treated with acetic acid 
(Fig. 12), it is mostly ejected and can be seen as a sharply-marked-off 
elliptic body, or sometimes somewhat kidney-shaped in figure, and of 
a granular appearance and bluish colour like that of many other kin- 
dred Ehizopoda, but does not appear to show any wall or surrounding 
investment, though sharply bounded. 
Probably, then, a stronger reason — one, indeed, that to some however 
may appear really but a very weak one — for doubting the strict iden- 
tity of either of my forms with Claparede and Lachmann's, resides in 
the seemingly different character of the pseudopodia, as seen in their 
figure, and as may be gathered from the text. In referring to the 
figure given by those authors I need hardly here guard against a 
possible misconception in supposing it is meant to be indicated that 
the pseudopodia originate equatorially from the periphery of the 
orbicular body, which would be contrary to the description." The 
specimen is drawn as viewed from above, the posterior part being to- 
wards the observer, and, though the pseudopodia really originate in a 
single tuft from the side turned away, they appear of course, seen from 
that point of view, to radiate around. In fact, all Ehizopoda of this 
character, that is, giving off the pseudopodia exclusively from an an- 
terior" end (such as Euglypha, Arcella, Difflugia, and many others) 
have a decided tendency to turn up (so to say) vertically, and creep, 
by action of the pseudopodia, along the surface on which they find them- 
selves. In fact, it is hard to get a ''Plagiophrys" to remain very long 
presenting to the observer a side or profile-view. The distinction, 
however, to which I allude is the coarse, granuliferous, and unbranched 
character of the pseudopodia, as shown in Claparede and Lachmann's 
figure as compared with the slender and hyaline and tufted tree-like 
bundle of very fitful pseudopodia presented by our form. In fact, the 
authors attribute to their genus Plagiophrys ' ' Actinophryan" pseu- 
dopodia ; now the form I have in view does not possess pseudopodia 
comparable to those of an Actinophrys nor to those of any heliozoan 
species. It is quite true Actinophryan" pseudopodia sometimes in- 
osculate, or even, occasionally, can temporarily divaricate, but I do not 
think they ever form a shrub-like or tree-like perpetually altering 
tuft, somewhat quickly appearing, branching, waving, extending, con- 
tracting, and, perhaps, as quickly disappearing, or at other times some- 
what rigidly maintaining themselves as a little tree. To some these 
may appear as too fine-drawn distinctions, but I cannot yet but think 
that these idiosyncrasies are, on the whole, characteristic in these 
forms. 
On the other hand, apart from these distinctions, we have in our 
rhizopod a minute globular body, with at least slender pseudopodia, 
emanating in one bundle, from a single little depression (or ^'boule," 
Clap, and Lachm.) at one side, and with an integument, which might 
perhaps, when seen only in the living example, appear only as a 
