29 
boniferous. Fishes are represented by the PalcBoniscus. Reptiles 
by the Archegosauriis, 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 IValchia, a 
Lycopod. 
South and West Walls of Hall 36.— Large slabs and 
casts showing tracks of reptiles of the Triassic period. Little is 
known about these animals, except so much as can be learned 
from their foot-prints. The Brontozoum was a three-toed animal, 
probably at least 14 feet in height, with a stride of over 3 feet. 
Cheirotherium (South Wall, Hall 59), was so named from the 
resemblance of the foot-print to the human hand. It was a four- 
or five-toed reptile, probably of the order of the Labyrinthodonts. 
A cast showing the shape of the skull of the latter animal may be 
seen at the right. ^ 
f Cases 5, 6, 7, part of 8, and Walls of Hall 59. — 
Fossils of Mesozoic time, the age of reptiles. This age is chaf- 
acterized by the number and size of its reptiles^ especially Amphi- 
bians. Here, too, are introduced the first mammals, birds and 
fishes of the modern type, and among plants the angiosperms. 
Cases 5A and B. — Triassic fossils. Many types of the 
Carboniferous Age continue to be prominent. Equisetimi, belong- 
ing to the family of Equisetae, or “ Horsetails ” of the present day, 
and Pterophylluniy of the order of Cycads, were most prominent 
among the land plants, and are illustrated by many specimens. 
Among the Lamellibranchs, the modern genus of Modiola is in- 
troduced. Ceratites represents the ■ Orthoceras of early times, 
from which it will be seen to differ in being coiled, and in having 
a more complex suture. 
Cases 5C, D, E, F, G, 6, 7, 8A, B, C, D and Walls 
of Hall 59. — Jurassic fossils. 
This is the period when the class of reptiles reached its great- 
est development. Other interesting fossils which are found, may, 
however, be first noticed. 
Cases 5E), E, F, G« — Among plants, Cycads are illustrated 
by several specimens of Cycadoidea. Among Invertebrates the 
beautiful Crinoid Pentacrinus, illustrated by three specimens on 
the south wall, is especially notable. Other Echinoderms are 
