240 NATURAL HISTORY SOCIETY OF DUBLIN. 
colour, and with a very delicate boundary, and the nucleolus shows 
itself as a somewhat darker dot therein posed somewhat to one side. 
The general cell contents are of a granular appearance, and of a greyish- 
blue tint, very like that of the so-called ‘‘ nucieus’’ in Ameeba, Difflugia, 
&c. &c. The cell-wall is thin and sharply defined, and presenting a 
somewhat yellowish tint; the contents not unfrequentiy are seen con- 
siderably receded from the wall, and possess a smooth boundary or 
outline. Self-division of the contents takes place by a complete fission 
into two within the outer wall, and often in such a stage a nucleus is 
to be seen in both parts of the so-divided mother cell; but I cannot say 
what becomes of the parent cell-wall upon the young cells attaining 
full form, nor whether they acquire a special cell-wall ere they should 
in any way become denuded of the mother celi-wall. The sarcode 
mass enveloping the cells is of a very great tenuity and very delicate, 
hence the covering glass, in order to preserve so fragile an organism for 
due examination, requires to be kept from bearing too heavilv upon it, 
by being let ana upon a piece of thin glass, or some such mode 8 
defence adopted, or by placing the dip in an animalcule cage, when the 
amount of pressure is thus under control. Emanating from this delicate 
sarcode mass the pseudopodia project to a greater or Tess extent into the 
surrounding water; these sometimes attain a considerable length, pro- 
bably twice the diameter of the body or more, and are then fewer in 
number than when they are more shortly projected, and sometimes 
do not radiate in all directions; they are sometimes rather short, and 
then more numerous, and then usually radiate more or less copiously 
all round. They are slender and pellucid, and mostly branch in a 
more or less irregular and subarborescent manner, becoming also not 
unfrequently mutually incorporated here and there in a reticulose 
manner. The branching takes place mostly near the base, but some- 
times one presents a somewhat tufted appearance near the upper 
extremity. Although very slender and colourless, the pseudopodia 
sometimes show distinctly the passage of very minute granules, and 
occasionally show slight protuberances or expansions at various points 
along their length. All these characters I have tried to portray in the 
figure (Pl. alike, fig. 2). Their motion or change of form is ordi- 
narily slow and somewhat languid, but is constant; for although 
persistent looking at them in an endeavour to trace their changes step 
by step is a draft on one’s patience, still, upon a few moments’ sus- 
pension of observation of them, and on again viewing them, very 
perceptible changes will have been seen to have taken place, not only 
in the branching and extension of the pseudopodia, but also in the 
mutual disposition of the group of central cells. But it certainly takes 
some amount of protracted observation to perceive all this—that is, the 
modifications of form characteristic of the rhizopodous nature. How- 
ever, the presence of foreign bodies entangled in the substance is not 
uncommon, in this respect unlike Raphidiophrys, in whose substance 
never yet any foreign bodies presented themselves. 
But if the slowness of the motion or change of figure of the pseu- 
