212 
ELEMENTS OF GEOLOGY. 
of Saumur, they form a soft building-stone, chiefly composed 
of an aggregate of broken shells, bryozoa, corals, and echino- 
derms, united by a calcareous cement; the whole mass being 
very like the Coralline Crag near Aldborough, and Sudbourn 
in Suffolk. The scattered patches of faluns are of slight 
thickness, rarely exceeding fifty feet; and between the dis¬ 
trict called Sologne and the sea they repose on a great va¬ 
riety of older rocks; being seen to rest successively upon 
gneiss, clay-slate, various secondary formations, including 
the chalk; and, lastly, upon the upp'er fresh-water limestone 
of the Parisian tertiary series, which, as before mentioned (p. 
142), stretches continuously from the basin of the Seine to 
that of the Loire. 
At some points, as at Louans, south of Tours, the shells 
are stained of a ferruginous color, not unlike that of the Red 
Crag of Sufiblk. The species are, for the most part, marine, 
but a few of them- belong to land and fluviatile genera. 
Among the former. Helix tuvonen- 
sis (Fig. 38, p. 56) is the most abun¬ 
dant. Remains of terrestrial quad¬ 
rupeds are here and there inter¬ 
mixed, belonging to the genera 
Dinotherium (Fig. 136), Mastodon, 
Rhinoceros, Hippopotamus, Chse- 
ropotamus^ Hichobune, Deer, and 
others, and these are accompanied 
by cetacea, such as the Lamantin, 
Morse, Sea-calf, and Dolphin, all of 
extinct species. 
The fossil testacea of the faluns 
of the Loire imply, according to 
the late Edward Forbes, that the 
beds were formed partly on the 
of low water, and partly at very 
moderate depths, not exceeding ten fathoms below that 
level. The molluscan fauna is, on the whole, much more lit¬ 
toral than that of the Pliocene Red and Coralline Crag of 
Suflblk, and implies a shallower sea. It is, moreover, con¬ 
trasted with the Suflblk Crag by the indications it afibrds of 
an extra-European climate. Thus it contains seven species 
of Cyprcea^ some larger than any existing cowry of the Med¬ 
iterranean, several species of Oliva^ Ancillaria^ Mitra^ Tere- 
hra^ Pyrula^ Faseiolaria^ and Go7ius, Of the cones there are 
no less than eight species, some very large,Vhereas the only 
European cone now living is of diminutive size. The genus 
Nerita^ and many others, are also represented by individuals 
Fig. 136. 
Dinotherium giganteum^ Kaup. 
shore itself at the level 
