23 
center of clay concretions, as may be seen in some which have 
been broken open. Sections of trunks of Lepidodendrids and 
Sigillarids, One of the latter shows by its size that the trunk 
of the original tree must have been many feet in diameter, and 
perhaps 80 to 100 feet high. Stigmaria, probably represent the 
under-water stems of the Sigillarids. 
The animal life of this period is characterized by the abun- 
dance of Crinoids. These reached their highest development at 
this time. Many specimens are shown, including Platycrinus, 
Scaphyctinus and Pentfeinitics, the latter a Blastid or bud crin- 
oid. Corals were also abundant, as represented by the column- 
ar Lithostrotion, a true polyp coral, and Dibunophyllum, a cup 
coral. The cork-screw-like Bryozoan Archimedes is illus- 
trated by several specimens. Spirit er and Productus are the lead- 
ing genera among the Brachiopods. The Gasteropods, univalve 
mollusks, are represented by Bellerophon and Pldurotomaria, 
Melonites was an Echinoid allied to the sea-urchin of the present 
day; it differs from the latter, however, in having large plates 
and small spines. 
Permian, or closing period of the Carboniferous. Fishes 
are represented by the Paleoniscus. Reptiles by the Archego^ 
saurus, an animal which combined the characters of reptile and 
fish, having both lungs and gills, and being covered with scales. 
Plants are represented by leaves of the Walchia, a Lycopod. 
A single floor case at the right contains a portion of a trunk 
of a tree of the Carboniferous Age. This tree was about two 
feet in diameter and the portion shown is six feet in height. On 
the wall an oil painting represents a forest of the Carboniferous 
Age, with ferns, clubmosses, equisetae, etc., grown to the height 
of forest trees of the present day. 
On the south wall is a series of twelve ideal landscapes of 
the different geological ages. 
HALL 36. 
Fossils of Mesozoic time, the age of reptiles. This age is 
characterized by the number and size of its reptiles, especially 
Amphibians. Here, too, are introduced the first mammals, birds 
and fishes of the modern type, and among plants the angios- 
perms. 
