254 
THE VOYAGE OF H.M.S. CHALLENGER. 
In its normal condition Saccammina sphcerica is readily distinguished from most of 
the other monothalamous species which resemble it in general contour — from the 
corresponding varieties of Pilulina, Technitella, and Pelosina by its hard rough firmly 
cemented test, and from Reophax difflugiformis by its relatively large size and thicker 
walls. From Psammosphcera fusca, the distinction, which depends primarily on the 
presence of a distinct aperture, is not so satisfactory, for specimens belonging unquestion- 
ably to the genus Saccammina are occasionally met with in which the orifice is exceed- 
ingly obscure, if not entirely wanting. 
In localities where the species is very abundant, the test often assumes anomalous 
forms. Sometimes individuals, crowded together at the sea-bottom, adhere to each other, 
in which case they either have separate orifices and remain in fact independent 
organisms, or, as is more common, they open into each other and constitute a sort of 
polythalamous test. Occasionally a larger fragment of rock is built into the wall, and the 
test has the characters of an adherent organism (PI. XVIII. fig. 14). In polythalamous 
specimens the additional chambers are smaller than the primordial one, and to some 
extent, therefore, supplementary ; in such cases the sandy investment of the terminal 
sphere is often incomplete, and shows numerous large openings amongst the sand-grains. 
An example with some of these peculiarities is represented in PI. XVIII. fig. 16. The 
large chamber adhering to two stones is the original test, and the remainder is 
supplementary, the smaller extremity being a mere mass of sand-grains with large 
interstitial openings. The chambers are sometimes connected in a straight line, as in the 
specimen under notice, but more commonly are combined in a less regular manner. The 
fusiform test, fig. 17, has two orifices, and closely resembles a single chamber of the 
fossil Saccammina carteri. Such variations from the typical form as those which have 
been described are more or less the result of accidental circumstances, and have little 
zoological significance. 
Saccammina sphcerica has been dredged on the coast of Norway — in Hardanger Fiord, 
Christiania Fiord, off Bergen, off Drobak, and elsewhere, by M. Sars, G-. 0. Sars, Norman, 
and others. Dr. Carpenter’s collection contains specimens from ten or more “Porcupine” 
Stations in the North Atlantic, situated west and south-west of Ireland, at depths of 
from 173 to 1443 fathoms ; and from one point in the Faroe Channel, 542 fathoms. It 
occurs in eight out of ten soundings made on the Austro-Hungarian Expedition, off the 
shores of Franz-Josef Land, in latitude 79° to 80° N., depth, 89 to 145 fathoms ; and in 
some of them it was the most abundant Foraminifer. It is reported also from deep 
water in the Bay of Biscay. It has only been found at two Challenger Stations, No. 246, 
near the very deep area of the North Pacific, 2050 fathoms, in which locality the specimens 
were built almost entirely of dead Globigerina shells ; and Station 155, depth 1300 
fathoms, near the Antarctic Ice-barrier, where a considerable number of individuals, 
indistinguishable from the North Atlantic type, were met with. 
