FOBAMINIFEBA EBOM THE NOBTH ATLANTIC AND ABCTIC OCEANS. 
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tribution, found in shallow water in the Adriatic and other warm seas, but usually 
frequent on sandy and muddy bottoms at not less than 30 fathoms and down to at least 
2350 fathoms. It is richest in numbers where there is nothing but the calcareous matter 
of Foraminifera. In the shallow water of our coasts Orbulina is poorly developed. 
We have not recognized it fossil in strata older than the Middle Tertiary period. 
In the North Atlantic the deep-sea soundings indicate that at 78, 90, 223, 329, 1660, 
1950, and 2050 fathoms 0. universa is rare and of middling size; at 2350 fathoms it is 
middle-sized and rather common; at 1776 and 2050 it is middle-sized and common; at 
415 fathoms it is large and common ; and at 1750 and 2176 fathoms it is large but rare. 
Genus Globigerina. 
Globigerina bulloides, D’Orbigny. Plate XIV. figs. 1 & 2 (Arctic) ; Plate XVI. fig. 15, 
and Var. infiata , figs. 16, 17 (North Atlantic). [See also Professor Huxley’s 
Appendix to Commander Dayman’s Admiralty Keport, p. 65, pi. 4.] 
Globigerina bulloides is the type of a distinct species, which is related to the monotha- 
lamous Orbulina on one hand, and to the polythalamous Botalince on the other. Its 
shell is composed of a series of hyaline and perforated chambers, of a spheroidal form, 
arranged in a spiral manner, and each opening by a large aperture around the umbilicus, 
in such a manner that the apertures of all the chambers are apparent on that aspect of 
the shell, and form a large “umbilical vestibule.” This opening of the chambers into 
one common vestibule is also characteristic of Carpenteria balaniformis. The extra- 
ordinarily wild manner of growth of the latter is, to a certain degree, represented in 
many of the larger specimens of Globigerina , which, losing the vesicular or botryoidal 
form, become flat, outspread, and loosely lobulated or palmate. Although in these 
respects, and also in the close resemblance of the young shells, these two species show 
a near alliance, yet Globigerina seems, on the whole, from its general neat habit of 
growth, and from its peculiar varietal groups, to be most nearly related to the Botalince 
(. Flanorbulina and Discorbina). In fact, Globigerina and its varieties form an interesting- 
group, Avhich may be regarded as central to the Planorbuline and Discorbine species and 
their varieties, as well as certain species ( Pullenia and Splicer oidina) which were not until 
lately recognized as related to the Botalince. 
The chief varieties of Globigerina are peculiarly isomorphic of these other forms. The 
large, extremely thick-walled, compact Globigerince , of the deepest waters, may stand as 
the isomorphs of the equally abyssal solid specimens of Sphceroidina ; nor are the two 
forms dissimilar at first sight. The smooth-walled compact Globigerince , such as have 
been named Gl. infiata , D’Orb. (Foram. Canaries, pi. 2. figs. 7-9), come near in structure 
to the highly polished, flush-celled, somewhat gigantic specimens of Pullenia obliquilo- 
culata, Parker and Jones* (the type of which is the so-called Nonionina sphceroides , 
D’Orb.) from great depths. We have already mentioned the wild-growing Globigerina 
* Caepentee’s ‘ Introd. Foram.,’ p. 183. See also Plate XIX. fig. 4. 
MDCCCLXY. 
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