290 NATURAL HISTORY SOCIETY OF DUBLIN. 
the lower pedicle-like extremity, just like the younger individuals in 
Clathrulina; and in one, as in the other case, it would look as if 
the germs establish themselves merely on the first solid support that 
becomes presented. Still, Greef would compare this occasional habit 
in Clathrulina almost to a kind of parasitism ; and, pushing the matter 
further, suggests the idea that the propinquity of the generations to one 
another is no accidental circumstance, but an adaptation for the pur- 
pose of securing such a proximity of individuals as would be essential 
for a possible or assumed sexual reproduction, and which would be 
otherwise denied to them, owing to this being a permanently fixed form 
on a rigid stipes. But if a sexual reproduction truly takes place (by 
‘‘conjugation’”’ or otherwise), the emerged Actinophryan bodies are just 
as free as any other Rhizopods, and would seem to stand in quite an 
analogous position, and under similar circumstances, as regards any 
possible sexual mode of reproduction. On the whole, then, I venture 
to think the suggestions put forward by Greef in this regard, as, at 
least as yet, very hypothetical. | 
To appreciate as completely as the interest of the subject deserves all 
the valuable considerations and remarks put forward by Greef, would 
indeed necessitate a careful perusal of his paper in full; and I am sure 
I ought to apologize if in so brief an epitome I have failed to indicate 
as accurately as ought to be the points put forward by him. Those 
who wish to pursue the subject further will have recourse to the ori- 
ginal; whilst, perhaps, though J have nought myself to add to what 
has before been done so much better than I could have hoped, my allu- 
sion to it here, and incorporation of Greef’s remarks, may not, I trust, _ 
be thought redundant. 
I attempt to add below brief diagnoses of those forms on Pl. X., 
which to my eyes assume a position to a great extent independent from 
the more common fresh-water Rhizopodous genera represented by Difflu- 
gia, but which, like those more nearly allied to the Radiolaria, seem to 
me not yet sufficiently known or defined to be placed in special recog- 
nised groups or orders. Hence they must just follow without any 
attempt thereat ; although, indeed, Claparéde and Lachmann place 
their Pleurophrys under Actinophryna, my figures, 1 to 6, seem to be 
as little comparable to that group as to Ameebina. I begin with— 
Genus, Pleurophrys (Clap. et Lachm.). 
Pleurophrys spherica ? (Clap. et Lachm.) Arch. 
PL EXT tig le 
Specific Characters.—Large, orbicular, elliptic, or somewhat wregu- 
larly shaped. Body not filling the cavity of the test, containing a large 
granular nucleus ; pseudopodia slender, slightly tapering, hyaline, pellucid, 
