Archer — On Freshwater Rhizopoda, 
91 
it might suggest itself just possibly that certain considerations might 
operate in a measure to exclude it from one and the same genus with 
Greeff 's. I allude to the mostly one-sided emanation of the pseudo- 
podia and the seeming absence of the coat at a given area and to the 
presence of the superficial hair-like processes, and the subtle hyaline 
sarcode envelope sometimes seen. The first circumstance might be 
thought to bear a parallelism to conditions constant in Pamphagus, 
Lieberkiihnia, &c., separating them from their allies — the second to 
represent a definite anterior opening (thus unlike Greeff 's forms) — the 
third to present a distinct portion of the organisation of the total rhizo- 
pod not evinced by Greeff 's forms — and the last, a greater amount of 
differentiation, or of superaddition of parts, indicating a certain 
advancement. But we have seen that all these are variable character- 
istics evinced in various degrees : these variations in reality, taken all 
together, constituting so much of the sum total of the characteristics 
of our rhizopod, whose nature is to show now some of them, now 
others, more prominently, or in a more pronounced manner — in other 
words, these characteristics, though attaching themselves to the species, 
are not of generic significance, Greeff' s figures of A. violaeea convey the 
idea of the pseudopodia being confined to a separate region, but he does 
not speak of this in the text. The peculiar elastic and yielding outer 
coat, penetrable by the pseudopodia, would seem to be the great 
character of the genus, coupled with the Amoeban body, and in that 
our form agrees. I need hardly say, its distinctions in itself from 
Greeff 's three forms are sufficiently striking. The vertical parallel 
closely-posed lines in the outer coat do not exist in them, nor do they 
show the hair-like processes, nor (of less importance) have they ever 
shown chlorophyll-granules. Indeed it is unnecessary to contrast them 
very rigidly or closely. Its possible relationship to Focke's ^^o. iii." 
(loc. cit.) has been above alluded to. ^' -Afiinities and Differences" can, 
however, be regarded from at least two points of view — a morphological 
and a developmental. Erom the former point of view enough has 
been demonstrated, indeed, to determine as to our form ; from the 
latter, nothing very reliable has shown itself to me. I have no doubt, 
however, but that earlier or later phases occur without a coat, and that 
it seems to be formed subsequently, as in Greeff' s forms, and others 
appertaining elsewhere. My data in that regard are, I regret to 
say, only obscure and conjectural. Should good fortune ever yield 
an opportunity to gain any insight into these points in connexion with 
our form, I may at some future time revert to our rhizopod herein 
described, which, morphologically viewed, seems to stand as a good 
species, and it may, for the present at least — with a double allusion, on 
the one hand, to the often well-developed covering of hair-like pro- 
cesses, and, on the other, to the less often seen hyaline and subtle 
outer envelope — pass as Amphizonella vestita. 
