REPORT ON THE FORAMINIFERA. 
429 
Cassidulina Icevigata is distributed, though by no means evenly, over a very wide 
area. It is one of the commonest of all arctic Foraminifera, occurring at almost every point 
at which soundings have been taken within the Arctic Circle. In the western hemisphere 
it has been found as far north as lat. 83° 19' N.; and in the eastern, to the shores of 
Franz-Josef Land, at about lat. 80° N. It is abundant over the whole northern portion of 
the North Atlantic, at depths ranging from 60 to 1600 fathoms, diminishing in frequency 
towards the equator, and is found in shallow water along the European coast-line. It is 
comparatively rare in the South Atlantic, but occurs off the Cape of Good Hope and in 
the Southern Ocean as far as the Antarctic Ice-barrier, lat. 65° 42' S. ; it is frequently 
met with amongst the islands of the South Pacific, at depths of less than 600 fathoms, being 
especially common amongst those of the west coast of Patagonia ; and it has also been 
obtained at three localities in the North Pacific : lastly, it has been collected both in the 
Mediterranean and the Red Sea. 
The geological distribution of the species does not extend further back than the 
beginning of the Tertiary epoch. It has been found in the London Clay of the Isle 
of Wight (Brady) ; in the Middle Tertiaries of various parts of Austria and Hungary 
(Reuss) ; in the later Tertiary formations of Central and Southern Italy (Jones and Parker, 
Seguenza, Terrigi) ; in the Crag of the eastern counties of England (Jones, Parker, and 
Brady) ; and in the Post-tertiary deposits of Norway (Sars, Crosskey and Robertson), 
of Ireland (Wright), and of the Island of Ischia (Vanden Broeck). 
Cassidulina crassa, d’Orbigny (PI. LIY. figs. 4, 5). 
Cassidulina crassa, d’Orbigny, 1839, Foram. Amer. Merid., p. 56, pi. vii. figs. 18-20. 
„ „ Id. 1846, For. Foss. Vien., p. 213, pi. xxi. figs. 42, 43. 
„ oblonga, Reuss, 1849, Denkschr. d. k. Akad. Wiss. Wien, vol. i. p. 376, pi. xlviii. 
figs. 5, 6. 
,, obtusa, Williamson, 1858, Rec. For. Gt. Br., p. 69, pi. vi. figs. 143, 144. 
, Icevigata, var. crassa, Parker and Jones, 1865, Phil. Trans., vol. civ. p. 377, pi. xv. 
figs. 5-7 ; pi. xvii. fig. 64, d. 
„ oblonga, Jones, Parker, and Brady, 1865, Monogr. Foram. Crag, App. I. II. pi. iv. 
fig. 16. 
„ crassa, Id. Ibid. App. I- H- 
The test of Cassidulina crassa is characterised by its oval outline and obtuse or 
rounded peripheral edge. It is relatively thicker than Cassidulina Icevigata, and the 
segments are fewer in number, and comparatively short and inflated. 
I can find no ground of distinction between this species and the Cassidulina oblonga 
of Reuss. The slight differences that appear in the figures are only such as may be 
observed in any collection of specimens, even from the same locality, and amount to no 
more than individual peculiarities. The species varies within certain limits, both in point of 
(SSOOL. CHALL. EXP. — PART XXII. 1884.) Y 55 
