Norwich Castle Museum. 154 
- Above the cases are arranged a number of heads 
of South African Buffaloes and Antelopes, and in 
the next room, devoted to Geology, is a handsome 
head of the African Elephant, which was too large to 
find a place here. 
Geology: Mineral and Fossil oil 
In Wall Case 1 there isa fine example of the trilobite, 
Calymene Blumenbachu. ‘The body of the trilobite con- 
sisted of three lobes, formed by successive rings or seg- 
ments, and had an armoured shield on its head ; most 
of them were furnished with a pair of crescentric eyes 
composed of many separate divisions or lenses. Many 
‘were able to roll up into a ball. The Silurian forma- 
tion, which like the Cambrian runs to an enormous 
thickness in Wales, 1s represented by examples of the 
Spirifer, a large brachiopod, and a sessile spreading 
coral called Favosites, and another named Cyathophyt- 
lum. In Table Case 3 will be observed some Silurian 
fossils, including Zerebratula, Airypa, Lituttes, etc. 
The first true “fishes are met with at the close of the 
Silurian period, but they become so numerous in the 
Old Red Sandstone that this has been called ‘‘ The 
Age of Fishes.” ‘These early forms of fishes, having 
an imperfect skeleton, were panoplied in shining 
armoured plates, and have therefore been called 
“sanoids.” Plant life comes in with the Silurian 
and Devonian formations. The vegetation became 
profuse in the Carboniferous or Coal-bearing era. 
What these early forms of plants were like we see 
in Wall Cases 1 and 2 in the specimens of Spheno- 
pieris, Calamttes, Lepidodendron, and Sigt'laria. The 
two last named exhibit the scars left by the scale-like 
outer covering of this extinct family of trees that grew 
so luxuriantly at this period. ‘These trees were, in fact, 
