Miscellaneous. 
393 
berg noticed a veiy interesting form among the microscopic prepara- 
tions put up with great neatness by Mr. Topping for sale. It is found 
in a certain kind of guano from Patagonia, and is one of the largest 
forms. Prof. Ehrenberg has called it Hemiptychus ornatus. They are 
isolated, comparatively very large, thin, discoid siliceous plates, which 
exhibit radii upon their surface connected by a very delicate network, 
after the manner of the genus Actinoptychus. These radii are like- 
wise in the present instance raised bands, but which, commencing at 
the margin, do not reach to the centre, but leave a broad central 
disc, in which these bands are continued in the form of finely punc- 
tated radial lines to the centre where a circle of teeth are visible : 
no marginal apertures were perceptible. 
Another new genus of Polygastrica was found in some guano 
from Patagonia brought by the Danish ship Waldemar. 
Like all the kinds of guano hitherto examined, this Patagonian 
kind contains a considerable number of siliceous-shelled Polyga- 
strica, together with numerous siliceous spicula of sea-sponges. 
The most interesting form is Entopyla australis, a new genus. Ex- 
ternally it has the greatest resemblance to Tessella, but in its in- 
ternal structure it more resembles the genus Biblarium. It forms 
quadrangular plates, which seen from the side are rounded off above 
and below. These quadrate tablets or boxes consist of several leaves 
like a book, which however are firmly connected. The leaves are 
parallel with the narrow sides and curved ; the two external leaves 
are like the cover of a book, thicker and marked with thirty-two 
horizontal ribs. These two outer decorated leaves resemble each 
other in Biblarium but not in Entopyla, where one is outwardly con- 
cave and the other outwardly convex. The concave outer leaf is 
upon the ventral side, since it exhibits two large roundish apertures 
at the extremities ; the opposite convex leaf has no aperture ; all the 
intervening leaves have a large aperture in the centre, leaving only 
a thin margin, thus forming a large continuous space in the interior 
of these little boxes. The structure in Biblarium is similar. 
This form is not quite new, a fragment of it having been brought 
from the Falkland Islands in the year 1843 ; it was then arranged as 
an imperfect but characteristic form with the genus Surirella, and 
called Surirella ? australis. It was a part of the cover of the Ento- 
pyla, which very much resembles the shells of Surirellce. 
This new guano contained — 
Polygastrica. 
Actinoptychus octonarius. 
Coccone'is oceanica. 
Coscinodiscus subtilis. 
Tessella Catena. 
Synedra Gallionii ? 
Zygoceros Rhombus? 
Grammatophora oceanica. 
serpentina. 
Entopyla australis. 
Gallionella sulcata. 
Grammatophora angulosa. 
Phytolitharia. 
Lithodontium furcatum. 
platyodon. 
Spongolithis Clavus. 
cenocephala. 
Fustis. 
