REPORT ON THE EORAMINIFERA. 
149 
between the successive modifications fail of application when the number of specimens is 
large , — Spiroloculina planulata, Spiroloculina nitida, Spiroloculina limbata, Spirolo- 
culina impressa, Spiroloculina excavata, and others, are but successive terms of a series 
in which every intermediate link can be supplied. Under these circumstances the 
distribution of each variety as distinct from its congeners must be taken with much 
reservation. 
The geographical range of the typical Spiroloculina planulata is very wide. It is 
abundant on our own shores, and is a common organism in littoral and shallow-water 
sands in temperate regions generally. It is not found in Arctic latitudes, and in the 
tropics its place is often occupied by closely allied varieties, such as Spiroloculina nitida. 
It is not at home in deep water, nevertheless Parker and Jones mention “ rare ” specimens 
in two soundings from the North Atlantic below 2000 fathoms. 
What appears to be a feeble modification of the species has been met with in the 
Lower Lias ; and well-marked specimens occur from time to time, in company with other 
Miliolce , in Tertiary deposits, from those of the Paris Basin (Louvres and Grignon) to 
the Crag of the eastern counties of England and the Pliocene of Italy. 
Spiroloculina nitida, d’Orbigny (PI. IX. figs. 9, 10). 
“ Frumentaria Sigma et Rliomhos,” Soldani, 1795, Testaceograpkia, vol. i., part 3, p. 239, pi. civ. 
figs. 1.1. mm. 
Spiroloculina nitida, d’Orbigny, 1826, Ann. Sci. Nat., vol. vii. p. 298, No. 4. 
„ „ Parker, Jones and Brady, 1871, Ann. and Mag. Nat. Hist., ser. 4, vol. viii. 
p. 248, pi. viii. fig. 24. 
Soldani’s drawing ( loc . cit., fig. II.), named by d’Orbigny Spiroloculina nitida, appears 
to be intended for one of the varieties of Spiroloculina planulata which differs from the 
typical form in its discrete or slightly inflated segments and the somewhat produced 
superior extremity of the final chamber. The complanate shallow-water Spiroloculina 
of the tropics are very variable in minor characters, but a considerable section of them, 
well typified by the figures PI. IX. figs. 9, 10, may be assigned to this particular form. 
Spirolocidina nitida is common in the coral-sands of the Indian and Pacific Oceans 
and of the Red Sea ; it occurs also in the Inland Sea of Japan, in the Mediterranean, 
and elsewhere. 
Soldani appears to have obtained the species from the Italian Tertiaries, as well as in 
the recent condition. 
Spiroloculina fragilissima, n. sp. (PI. IX. figs. 12-14). 
Test nearly circular, complanate, extremely thin ; peripheral edge rounded. Segments 
numerous, much curved, the later ones in adult specimens nearly semicircular. Shell- wall 
(ZOOL. CHALL. EXP. — PART XXII. — 1883.) Y 20 
