726 
THE YOYAGE OF H.M.S. CHALLENGER. 
has been observed in the Arctic Seas, as far north as lat. 82° 33' N., and it is abundant 
on the European shores of the North Atlantic. Though less common within 
the tropics, it occurs from time to time amongst the islands of the South Pacific, 
in the South Atlantic, the Red Sea, and elsewhere. Notwithstanding that a few 
poorly- characterised specimens have been met at the greater depths of the ocean, the 
home of the species is on bottoms of less than 50 fathoms, and it is the only member 
of the genus that is common in estuaries and brackish- water pools. 
Under one name or other the form has been identified in the Eocene formation 
of Paris (Terquem), in the Miocene of Vienna (d’Orbigny), and of Calabria (Seguenza) ; 
in the Pliocene of the Island of Rhodes (Terquem), and in the Post-tertiaries of Norway 
(Sars, Crosskey, and Robertson), and of various parts of the British Islands (Robertson, 
Wright, Shone). 
Nonionina umbilicatula, Montagu, sp. (PI. CIX. figs. 8, 9). 
Nautilus umbilicatulus, Montagu, 1803, Test. Brit., p. 191 • — Suppl., p. 78, pi. xviii. fig. 1. 
Nonionina soldanii, d’Orbigny, 1846, For. Foss. Vien., p. 109, pi. v. figs. 15, 16. 
,, „ Costa, 1856, Atti dell’ Accad. Pontan., vol. vii. p. 201, pi. xvii. fig. 11. 
„ polystoma, Id. Ibid. p. 206, pi. xiv. fig. 10. 
„ barleeana , Williamson, 1858, Bee. For. Gt. Br., p. 32, pi. iv. figs. 68, 69. 
Polystomella crispa, var. ( Nonionina ) umbilicatula, Parker and Jones, 1865, Phil. Trans., 
vol. civ. p. 405, pi. xiv. fig. 42, a.b.; pi. xvii. figs. 58, 59. 
Nonionina formosa, Seguenza, 1879, Atti B. Accad. dei Lincei, ser. 3, vol. vi. p. 63, pi. vii. fig. 6. 
„ umbiliqata, Terquem, 1882, Mem. Soc. geol. France, ser. 3, vol. ii., M6m. III., p. 42, 
pi. ii. fig. 7. 
Nonionina umbiliculata forms a good quasi-specific type, embodying characters about 
midway between those of Nonionina depressula and Nonionina pompilioides. From 
the former it is distinguished by its more compact build and deeply sunk umbilici, from 
the latter by its relatively depressed contour and larger number of chambers. 
It is a cosmopolitan form, its area of distribution reaching from Smith Sound and 
the shores of Franz- Josef Land, about lat. 80° N., to the south of Patagonia, about 
lat. 51° S. It is abundant in the North Atlantic and South Pacific, and scarcely less 
so in the South Atlantic and North Pacific, and occurs also in the Indian Ocean, the 
Southern Ocean, the Mediterranean and the Red Sea. The bathymetrical range extends 
from 30 or 40 fathoms down to 3125 fathoms. 
Fossil examples have been obtained from the Eocene of the Paris Basin (Terquem), 
from the Septaria-clay and Upper Oligocene formations of Central Europe (Reuss), from 
the Miocene of Vienna (d’Orbigny), and of Calabria (Seguenza) ; from the later Tertiaries 
of Italy (Costa), from the Pliocene of the Island of Rhodes (Terquem), from the Post- 
pliocene of Norway (Sars), and of Cheshire (Shone), and from the sub-recent Fen-clay 
of Cambridgeshire (Parker and Jones). 
