568 Transactions of the Society. 
the end of the final segment, though not at the extremity of the 
entire shell. 
Two years or more ago * my friend Mr. W. H. Harris, then of 
Cardiff, brought me a mounting with two or three specimens of a 
Foraminifer, the characters of which did not appear to coincide with 
those of any hitherto described species. The shells, however, were 
very minute and their structure obscure, and it appeared better to 
wait for further material before attempting to work out the points of 
difficulty they presented. From time to time I have received further 
specimens from the same correspondent, and I now propose to give 
as full a description of them as circumstances permit. 
Some of the shells referred to are of smaller size than the rest, 
and whilst possessing the same general features, exhibit certain minute 
structural differences. Whether the larger and smaller specimens 
represent different conditions of the same organism or two independent 
species, the material at my command is insufficient to determine 
satisfactorily. The present description applies primarily to the larger 
form, which in any case may be regarded as the type of the genus. 
The accompanying woodcuts, from very careful drawings by 
Mr. Hollick, give an accurate idea of the general features of two of 
the larger shells. The largest example I have seen is scarcely 
1/100 in. (0*25 mm.) in length, and somewhat resembles a com- 
pressed Biloculina , though of less symmetrical configuration. The 
outline is approximately oval, more or less inequilateral, broader 
towards the aboral end, tapering a little towards the oral extremity ; 
one face of the shell is convex, the other nearly flat, and the peripheral 
edge sharp and subcarinate. The margin of the broad aboral end is 
serrate, the teeth being irregular as to size and disposition. The 
smaller specimens, above referred to, have even margins, without 
carina or serration. The aperture is simple, and consists of a long 
narrow opening, surrounded by a thickened lip, occupying the 
superior extremity of the test. The shell-wall is exceedingly 
thin and transparent, and distinctly porous, the perforations being 
minute and evenly distributed. Owing to the small size and 
extreme fragility of the shell, it is almost impossible to study its 
internal structure by means of sections ; nor is this needful, inasmuch 
as the condition of the interior is readily made out from specimens 
mounted in Canada balsam, and viewed by transmitted light. From 
a shell so mounted (fig. 2) it may be seen that the adult organism 
consists of about seven segments ; that the primordial chamber is 
round, and that it is followed by another of similar size and shape ; 
that these are partially embraced by a long, arched, Milioline chamber 
with terminal aperture, and that this again is succeeded by one of 
like contour on the opposite side, with the aperture at the opposite 
end. The three remaining chambers each completely envelopes those 
In June 1888 . 
