262 NATURAL HISTORY SOCIETY OF DUBLIN. 
use of clear quartzose granules. These must be impacted on a basis of 
that colour, which gives it the tawny hue. I have not seen a nucleus. 
This is the only one of these forms I have seen ‘‘ conjugated,” in which 
position pairs are not unfrequently met. 
The character of the pseudopodia in these forms is very like that 
of the pseudopodia of Draphoropodon mobile. I do not mean the long, 
extravagantly drawn-out ones, but the tufted ones at the sides or after 
the retraction of the very long ones. The nucleus seen in Fig. 1, too, 
is very like that of fig. 6, and hence the consideration of the three 
forms just drawn attention to naturally follows after the latter. 
Amphitrema Wrightianum (gen. et sp. nov.), Pl. X., figs. 4, 5. 
The two drawings presented (figs. 4 and 5), taken along with the 
explanation of the Plate, convey, I might say, all I am able to offer 
upon this curious little form. This Rhizopod possesses an elliptic com- 
pressed translucent test, bearing impacted thereon a number of gra- 
nular foreign particles, each face being comparatively free from these, 
which are most crowded along the margins and edges. At each op- 
posite end there exists a rounded aperture, through which emanates a 
dense shrub-like tuft of more or less branched, linear pseudopodia, 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 some- 
times happens that one of the apertures becomes stuffed up by foreign 
granular particles clustered in a heap, so much 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 get 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 ren- 
dering 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 completely fill the 
test. It is always densely loaded with chlorophyll 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 I 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 Diplophrys Archeri (Barker).* To the seeming distinc- 
tions of these two forms in a generic point of view I shall allude 
below ; in an individual or specific point of view no two forms could 
* « Quart. Journ. Mier. Sci.,” vol. xvi., p. 128, in “‘ Proceedings of Dublin Microsco- 
pical Club,’’ December 19, 1867. 
