32 
Cephalopods. They are of the same type as Orthoceras, but are 
coiled and the junction of the septa and shell (suture) is zigzag 
instead of straight. Bothriolepis—<^2,wo\A fish. Note the thick, 
bony plates or armor. 
Cases 4A, 4B, 4C, 4D, and 5A.— Fossils of the Car- 
boniferous Age, or age of coal plants. Naturally, land plants are 
the striking features of this age. They belong to five great fami- 
lies: Conifers, Ferns, Lepidodendrids, Sigillarids, and Calamites. 
Cases 4A, 4B, 4C, 41), Hall 36. — Cordaites, This 
tree is allied to the Conifers, and had probably a straight trunk 6o 
or 70 feet in height. Trigonocarpmn, in the same case, is sup- 
posed to represent its fruit. Ferns are represented by 
Neuropteris and others, many imprints of sections of the fronds 
being shown. These frequently form the center of clay concre- 
tions, as maybe seen in some which have been broken open. Sec- 
tions 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 
abundance of Crinoids. These reached their highest development 
at this time. Many specimens are shown in this case, including 
PlatycrinuSy Scaphycrinus, and Pentre^nites, a Blastid or bud 
Crinoid. Corals were also abundant, as represented by the 
columnar Lithostrotiony a true polyp coral, and Dibunophylluniy 
some polished slabs containing which are shown. The cork-screw- 
like ArchBnedes is illustrated by several specimens 
Spirifer and Productus are the leading genera among the Brachi- 
opods. The Gasteropods, univalve mollusks, are represented by 
Bellerophon and Pleurotomaria, MeloniteSy in the upper part of 
Case4, 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. The cast on the wall shows the foot-prints of one of 
the first reptiles, Sauropus. This was a four-footed, crawling animal, 
with thick, fleshy feet about 4 inches long. 
Case 5 A, Hall 39. — Permian, or closing age of the Car- 
boniferous. Fishes are represented by the Palceoniscus. Reptiles 
hy ArchegosauruSy2a\ animal which combined the characters of 
reptile and fish, having both lungs and gills, and being covered 
