AND DISTRIBUTION OF TRILOBITES. 287 
tion. It contains other crustaceous remains besides the Phillipsia 
and Griffithides, which approach to the orders of the genuine 
Pecilopoda and Phyllopoda, viz. Limulus and Dithyrocaris. 
3. France.—France, notwithstanding the extent of the transi- 
tion formation, is a country poor iu its fossils. This may be owing 
to the predominance of the clay-slate. The whole mountainous 
north-west of the country, Normandy, Bretagne, and the district 
on the lower Loire, consists of it for the greater part. The occur- 
rence of Ogygia Guettardi and Desmaresti at Angers is well 
known, likewise that of the Cal. Tristani in the Cotentin; less 
so that of the English Trinuclei (T. Caractaci) at Ste. Bregitte 
in Normandy in a clay-slate which contains Chiastolite: all of 
these slates most probably belong to the lower Silurian system. 
Besides the Trilobites mentioned, I only further know of a Ho- 
malonotus from the red sandstone of Caen, an evidently younger 
link of the upper Silurian system. 
4. Germany.—The paleozoic rocks occur here over a very 
considerable extent at five localities. Of these, the large plateau 
of the Lower Rhine occupies the first place; uniformly resting 
on its undulating ridge, abounding in picturesque valleys, of 
which many deserve to hold an equal rank with the celebrated: 
* Valley of the Rhine,” it extends at an average level above the 
ocean from the Sambre in Belgium to the Diemel in the west, 
accompanied towards the north and south by the richest coal 
formation of the continent (Valenciennes, Namur, Liege, Esch- 
weiler, Essen, in the north; Saarbriicken in the south). Both 
transition and coal formation contain Trilobites as widely dif- 
fused as in those of England. The plateau of the Voigtland 
is far inferior to the former in extent; it, nevertheless, extends 
from Bless near Schalkau to the neighbourhood of Freiberg, 
and from Gera on the Elster to the crystalline slates of the 
Fichtel mountains. The grauwacke and clay-slate plateau of 
the Hartz, which island-like elevates itself from the younger 
surrounding formations, is of still less extent. The fourth Ger- 
man locality is in the interior of the Bohemian basin ; it occupies 
a triangle like the preceding one, which extends from Prague to 
near Klattau, and is turned with its western side towards the 
Bohemian Forest. It bears in its centre the somewhat consider- 
able coal measures of Bohemia. Finally, of the fifth, or Upper 
Silesian-Moravian Grauwacke system, we know but too few 
Trilobites to render it worthy of particular notice. Upper Si- 
x 2 
