278 NATURAL HISTORY SOCIETY OF DUBLIN. 
tioned, readily cast off, and appear to me sometimes as if they became 
collapsed in specimens some time kept. On my first meeting with this 
form, I doubtfuliy regarded it as possessing an outer sarcode border or 
region containing the hyaline globules; but by a renewed examination, 
I have now little doubt but that such actually exists, though of 
considerable tenuity, and very pale in colour. I had likewise supposed 
that, amongst fresh-water Rhizopoda, it was without a parallel in the 
red pigment granules; but that statement must be modified, inasmuch 
as some of the forms belonging to Greef’s new genus Astrodisculus also 
show red granules in their interior; but our form by no means belongs 
to that genus. I doubt not, however, that the present is actually 
identical with another of Greef’s forms, as I have indicated above 
-—I mean that which he has named Hyalolampe fenestrata. But, as my 
description and nomenclature preceded his, mine naturally takes the 
priority, and his name falls to the rank of a synonym. But whilst, in- 
deed, I have no doubt of the correctness of this assumption, as will be 
seen I am necessarily at variance with Greef in my interpretation of the 
structure of the form in question. I myself have not been able to see any 
‘“‘nuclear’’ structure. Greef’s account of his Hyalolampe (equivalent 
to my Pompholyxophrys) runs thus: —‘‘ This form is surrounded by a 
beautiful siliceous shell, which appears to be composed as if of indivi- 
dual glass globules laid upon one another. At first glance I imagined that 
Thad before me an alveolar vacuolar (schaumiges) sarcode-net; but I soon 
satisfied myself, by an examination of the contours, that this was of the 
former structure.’ He then goes on to say that he satisfied himself of 
the siliceous nature of what he regards as a true perforate case (Gitter- 
haus; Gittergehause) by the application of acetic acid, caustic potash, 
and even sulphuric acid; and he would refer this form, along with Cla- 
thrulina, to the Ethmospherida. Now, if am at all right in believing our 
forms to be one and the same, I very deferentially think this account of 
the structure is inaccurate; as I have already described, I do not think 
this form is surrounded by a ‘‘ Gittergehiuse ;”’ the globules are free and 
separate, included by a delicate sarcode layer, and sometimes (I think) 
appear even collapsed; they are not comparable to the solid, fenestrate, 
true ‘‘ Gittergehause’’ of Clathrulina, and, in fact, this form in the pos- 
session of these structures stands alone, so far as I can see. The crea- 
ture is not all uncommon in our moor pools, and I only wonder it has 
hitherto been overlooked; itis, however, minute, and never to my eyes 
has shown any stage of development, and but seldom shows any incepted 
food, though sometimes, indeed, distorted by an unusually large morsel, 
and the rejectamenta discharged by a sudden effort, which could hardly 
be the case if enclosed in a solid or connected ‘‘ Gittergehause.” But as 
Grecf has more to convey on the forms brought forward by him, per- 
haps he may hereafter clear up my difficulties, and remove the apparent 
discrepancies. 
