Nomenclature of the Foraminifera. 33 
the still greater potency of the umbilical system of cells is here 
the sole cause of variation. Many of the globular specimens 
have an irregular hole or subcylindrical cavity, bevelled off at 
the margin, on some part of the surface: this is the remnant of 
the earlier concavity of the base, the edges of which, growing 
downwards and inwards, have failed to meet and to make up a 
perfect globe. 
This little spherical Orbditolina, which may be termed O. lavis*, 
is very common. It occurs also at Fiji, in the West and East 
Indies, in the Mediterranean, and on the British coast, as far 
north at least as the Isle of Arran. It is found in the shelly 
sands of rather shallow water; whilst the little Orbitolina corru- 
gata, inhabiting the same seas, lives at a greater depth, on muddy 
bottoms and in shell-sands. In the fossil state the globular form 
is found in the Tertiary beds of Palermo, Bordeaux, and San 
Domingo. The last yields the largest. 
8. Among the spherical specimens from the Rewa reefs of 
Fiji there are some rather flattened individuals (having the same 
essential structure as those described above, and 3 inch in dia- 
meter), which present at their margin one or more small conical 
or nipple-like processes, composed of cells similar to those of the 
body, but more compressed. In other specimens these projec- 
tions are larger and give a lobulate form to the shell, the outline 
being somewhat like that of an ivy-leaf, and imitating Calcarina 
Spengleri, or Polystomella unguiculata with thickened spines. 
Other individuals have subcylindrical spines which do not always 
lie on one plane. The length of the spine sometimes exceeds the 
diameter of the body of the shell. Similar forms occur on the 
coasts of New Zealand. 
Dr. Carpenter has lately shown us that in these spinous and 
stellate forms the growth of the shell is symmetrical, the two 
convex surfaces having about equal proportions of the annular 
tiers of cells. The vertical section in such forms reminds one 
of the structure of Orbitoides, excepting,—1st, that in the latter 
and flatter Foraminifer the two surfaces of the sheli are unequal; 
2ndly, the over- and under-lying cells have usually an irregu- 
larity of arrangement ; and 3rdly, the central cells are small, 
but numerous, regular, and distinct. 
Coexistent with the habit of producing lobes or processes (as 
holds good also in Calcarina and Polystomella), we find an in- 
creased development of the interlocular or canalicular passages, 
to the sarcode of which the granulations and overgrowths in 
other forms are due. Here we find smooth, minute, glossy 
* On account of the absence of the roughly limbate septal edges seen in 
some other varieties. 
Ann. & Mag. N. Hist. Ser. 3. Vol. vi. 3 
