CHALK OF FAXOE. 
285 
accumulated in a sea in which the belemnite and other cre¬ 
taceous mollusca flourislied. 
Pisolitic Limestone of France. —Geologists were for many 
years at variance respecting the chronological relations of 
this rock, which is met with in the neighborhood of Paris, 
and at places north, south, east, and west of that metropolis, 
as between Vertus and Laversines, Meudon and Montereau. 
By many able palaeontologists the species of fossils, more than 
fifty in number, were declared to be more Eocene in their ap¬ 
pearance than Cretaceous. But M. Hebert found in this for¬ 
mation at Montereau, near Paris, the Pecten quadricostatus^ 
a well-known Cretaceous species, together with some other 
fossils common to the Maestricht chalk and to the Baculite 
limestone of the Cotentin, in Normandy. He therefore, as 
well as M. Alcide d’Orbigny, who had carefully studied the 
fossils, came to the opinion that it was an upper member of 
the Cretaceous group. It is usually in the form of a coarse 
yellowish or whitish limestone, and the total thickness of the 
series of beds already known is about 100 feet. Its geograph¬ 
ical range, according to M. Hebert, is not less than 45 leagues 
from east to west, and 35 from north to south. Within these 
limits it occurs in small patches only, resting unconformably 
on the white chalk. 
The Nautilus Danicus^ Fig. 230, and two or three other 
species found in this rock, are frequent in that of Faxoe, in 
Denmark, but as yet no Ammonites, Hamites, Scaphites, Tur- 
rilites, Baculites, or Hippurites have been met with. The 
proportion of peculiar species, many of them of tertiary as¬ 
pect, is confessedly large ; and great aqueous erosion suffered 
by the white chalk, before the pisolitic limestone was formed, 
affords an additional indication of the two deposits being 
widely separated in time. The pisolitic formation, therefore, 
may eventually prove to be somewhat more intermediate in 
date between the secondary and tertiary epochs than the 
Maestricht rock. 
Chalk of Faxoe. —In the island of Seeland, in Denmark, the 
newest member of the chalk series, seen in the sea-cliffs at 
Stevensklint resting on white chalk with flints, is a yellow 
limestone, a portion of which, at Faxoe, where it as used as a 
building-stone, is composed of corals, even more conspicuous¬ 
ly than is usually observed in recent coral reefs. It has been 
quarried to the depth of more than 40 feet, but its thickness 
is unknown. The imbedded shells are chiefly casts, many of 
them of univalve mollusca, which are usually very rare in 
the white chalk of Europe. Thus, there are two species of 
Cyprma^ one of Oliva^ two of Mitra^ four of the genus Ccri- 
