REPOET ON THE FORAMHSTIFERA. 
611 
logical point of view the cli- or tri-thalamous condition is nothing more than an abnormal 
or accidental development of the typical form. 
In point of distribution Orbulina universa is a cosmopolitan species. It has been 
taken in the tow-net as far north as the Faroe Channel, and thence southward as far as 
lat. 32° 24' S. in the Atlantic, and 45° 31' S. in the Pacific. In bottom-dredging's its 
occurrence has been noted at every latitude from the shores of Novaya-Zemlya, lat. 76° 
59' N., almost to Magellans Strait, lat. 50° 10' S. It inhabits all the great oceans, the 
Eed Sea, the Mediterranean, and the Adriatic. In some areas the shells exist in enormous 
numbers ; and at certain points in the North Atlantic, two or three degrees south and 
south-west of Ireland, explored on the second “ Porcupine ” cruise, they form one of the 
most important constituents of the bottom-ooze. 1 
The earliest geological appearance of the species is in the Lias of the Moselle 
(Terquem). It has been noticed in certain Jurassic limestones of the Canton Aargau, 
Switzerland (Haeusler), and in the Chalk of the Island of Etigen, and at Volsk in Eussia 
(Ehrenberg). It occurs in the Septaria-Clays and in the Upper Oligocene formations 
of Germany (Eeuss) ; in the Miocene of the Vienna Basin (cl’Orbigny, Eeuss, Karrer), 
and of Malta (Brady) ; in the Salzthon of Wieliczka (Eeuss), and in the later Tertiaries 
of Central and Southern Italy (d’Orbigny, Costa, Terrigi, &c.). 2 
Orbulina porosa, Terquem (Pi. LXXXI. fig. 27). 
Globulina porosa, Terquem, 1858, Foram. du Lias, l l6rc mem., p. 633 , fide Terquem. 
Orbulina liasica, Id. 1862, Ibid. 2 i6me mem., p. 432, pi. v. fig. 4. 
„ foveolata (?), Seguenza, 1862, Foram. Monotal. Mess., p. 37, pi. i. figs. 1, 2. 
„ neojurensis, Karrer, 1867, Sitzungsb. d. k. Ak. Wiss. Wien, vol. lv. p. 368, pi. iii. 
fig. 10. 
„ „ Norman, 1876, Proc. Roy. Soc., vol. xxv. pp. 213, 214. 
Globigerina ( Orbulina ) neojurensis , Brady, 1879, Quart. Journ. Micr. Sci., vol. xix., N. S. 
p. 76. 
„ „ ,, Terrigi, 1880, Atti dell’ Accad. Pontif., ann. xxxiii. p. 186, 
pi. i. fig. 16. 
The shell of this species is spherical and coarsely perforated, and the pores 
are surrounded externally by exogenous ridges which mark out the surface into 
1 Samples of tbe bottom-ooze from “ Porcupine” Stations 36 and 42, as they reached my hands, were almost entirely 
composed of Orbulince. It has been suggested that the material from these points had been partially washed on ship- 
board. I have no certain knowledge that this is the case, but it seems not improbable, inasmuch as in another sample 
from Station 42, preserved by Sir Wyville Thomson, the same preponderance is not apparent. Nevertheless, it is 
a significant fact that Orbulince do exist in these enormous numbers, and their abundance in proportion to other 
organisms of similar size is not diminished by the suggested explanation. 
2 Abich, in a recently published memoir (Geol. Forsch. in den kaukasischen Landern, II. Th., 1 Westhalfte, p. 240, 
pi. xi. fig. 8) has described an early Tertiary rock from the region of the Caucasus as an OrhwKwa-limestone (“ Orbulinen- 
kalk”). It is evident, however, both from the description and figure, that this is nothing more than one of those 
calcareous deposits formed of oolitic grains, which are to be met with in formations of every age, from the Silurian 
