702 
MIDDLE. 
LOWER. 
Belgium and the North of France. 
(Givetien. The great limestone of 
the middle Devonian series, well 
seen at Givet. Among theabundant 
characteristic fossils are Spirifera 
mediotexta, Sp. undifera, Stringo- 
cephalus Burtini, Uncites gryphus, 
Megalodon cucullatus, Murchisonia 
coronata, M. bilineata, Cyatho- 
phylum quadrigeminum, Heliolites 
porosa. 
In the basin of Namur the con- 
glomerate of Pairy-Bony lies below 
the limestone, and contains a band 
of sandstone with plants (Lepido- 
\ dendron Gaspianum). 
(Eifélien, Shales (Schistes de 
Couvin), with Calceola sandalina, 
Phacops latifrons, Spirifera curvata, 
Sp. subcuspidata, Sp. elegans, 
Spirigera concentrica, Pentamerus 
galeatus, Strophalosia productoides, 
&e. ; 
Coblenzien or Grauwacke, com- 
posed of four zones of greywacke, 
sandstones, shales, and conglomerate 
(Poudingue de Burnot, Abrien, 
Hundsriickien), with Pleurodictywm 
problematicum, Chonetes plebeia, 
Strophomena depressa, Strophomena 
daleidensis, Leptena Murchisonii, 
Rhynchonella orbignyana, Spirifera 
subeuspidata, Sp.  cultrijugata, 
4 Sp. paradoxa, Calceola sandalina, 
numerous Pterinex. 
Taunusien, consisting of the Gres 
d’Anor (Spirifera paradoxa, Sp. 
Bischoff, Spirigera undata, &e.). 
Gedinnien, comprising an upper 
group of shales and sandstones 
and a lower group of fossiliferous 
shales, quartzo-phyllades, quart- 
zites, and conglomerates. ‘The 
fossils in the lower group comprise 
Dalmanites, Homalonotus Romeri, 
Primitia Jonesti, Tentaculites gran- 
dis, T. irreqularis, Spirifera Mercuri, 
Orthis Verneuili, Pterinea ovalis, 
&e. 
am 

Rhineland. *~ 
(b) Stringocephalus group, ¢onsist- 
ing of the great Hifel limestone 
with underlying crinoidal beds 
(Stringocephalus Burtini, Spirifera 
undata, Productus subaculeatus, 
Pentamerus galeatus, Atrypa re- 
ticularis, Calceola sandalina, and 
many corals and crinoids), 
(a) Calceola group,—marly lime- 
stones full of Calceola sandalina, 
Spirifera concentrica, Camaro- 
phoria microrhyncha, &e., resting 
upon impure shaly ferruginous 
limestone and greywacke, marked 
by an abundance of Spirifera 
cultrijugata, Rhynchonella Orbig- 
nyana, Atrypa reticularis, Phacops 
latifrons, &c. 
c) Upper Greywacke (Vichter- 
schichten), with Chonetes sarcinu- 
lata, Ch. dilatata, Rhynchonella 
orbignyana, numerous Pterinez. 
(b) Ahr group,—greywacke shales 
with Chonetes sarcinulata, C. 
dilatata, Rhynchonella Livonica, 
Spirifera paradoxa, Sp. speciosus, 
many species of Pterinea, Plewro- 
tomaria, and Murchisonia. 
(a) Coblentz group, greywacke and 
clay-slate (Leptena  laticosta, 
Chonetes sarcinulata, Rhyneho- 
nella Livonica, Plewrodictyum 
problematicum, &c.). 
In the Harz, according to the researches of F., Roemer and K. A. 
Lossen, the Devonian system, which is there largely developed, consists 
c, 
STRATIGRAPHICAL GEOLOGY. — [Boox VI. 
‘ 
of a lower group of quartzites, greywackes, flinty slates, clay slates, and — 
associated bands of diabase, a middle group composed of the characteristic 
Stringocephalus-limestone with diabase tuffs, and an upper group 
consisting of limestones, shales, and schalsteins, with the usual Spirifera 
Vernewli and Entomis serrato-striata, Representatives of the same system 
reappear with local petrographical modifications, but with a remarkable 
