144 
THE LOWER GALLERY. 
shales, sandstones, limestones, ironstones, and coal seams, many 
of the beds being extremely rich in organic remains. The Flat 
Cases 36 to 49 are devoted to carboniferous fossils, among which 
the brachiopods are especially conspicuous ; many of the speci- 
mens of Productus and of Spirifera from the Carboniferous 
Limestone being exceptional for size and beauty of preservation. 
The trilobites, on the other hand, are but small and of few 
genera, the tribe being evidently on the eve of extinction. In 
Wall Case 12 is a large suite of beautiful corals and crinoids, 
illustrating most of the forms with which the Carboniferous 
Limestone is, in many localities, crowded. A Table Case (D), in 
Recess No. 17, contains also a fine series of polished corals 
from the Carboniferous Limestone near Bristol. The Cephalopods 
in Wall Case 13 are of much interest, including such forms as 
the straight-chambered shell termed Orthocevas, the familiar 
genus Nautilus, still living, and the nautiloid shell, with zig- 
zagged sutures, called Goniatites. Near the eastern staircase 
is a gigantic Orthoceras , nearly six feet in length, from the 
Carboniferous Limestone of Holy Island, off the coast of 
N orthumberland. 
Attention will be attracted, as the visitor passes the 
Wall Cases 14 and 15 , by the large series of plant-remains, 
representing the terrestrial vegetation of the coal-measures. 
The principal types of the carboniferous flora are referable to 
flowerless plants, and include numerous genera of ferns ; plants 
allied to the horse-tails, but of larger growth, such as the 
Catamites ; and those which, though in many cases of gigantic 
size, find their nearest modern representatives in the humble 
club-mosses ; such are the well-known fossils called Lepido- 
dendron and Sigillaria, with their roots or rhizomes termed 
Stigmaria , and the spore-bearing cones known as Lepidostrobi. 
In the Wall Cases placed in the Recesses 16 to 18 are 
jiumerous specimens illustrating the carboniferous vertebrata, 
and including the teeth and spines of various fishes, especially 
sharks, from the Carboniferous Limestone. The large Rkizodus, 
a ganoid from the coal-measures, is especially noteworthy, one of 
its teeth, here exhibited, measuring as much as five inches in 
length. It is in the coal-measures that we find the earliest 
examples of those vertebrata, which, during part of their life, must 
have been exclusively air-breathers. The Anthracosaurus and 
Loxomma are examples of such forms. These are all known as 
Labyrinthodonts — so called from the curious structure of certain 
teeth as displayed in microscopic sections. They belonged to the 
class Amphibia, which contains the frogs, toads, and newts, and 
which may be separated from the Reptiles by having respiration 
effected in early life by means of gills. 
The Permian system, which overlies the Carboniferous, and is 
usually regarded as marking the upper limit of the Palaeozoic 
strata, has its fauna illustrated chiefly in Table Cases 50 and 51. 
The shells, mostly small and in some cases distorted, are from 
the Magnesian Limestone : whilst the fishes, such as the ganoid 
