Department of Geology 
The collections of this Department illustrate the subject of 
geology and its subdivisions of paleontology, mineralogy, eco- 
nomic geology, and geographic geology. The collections are 
grouped so as to represent these subdivisions separately and also 
form a comprehensive whole. The collections occupy three halls 
of the main building and the entire west wing. The total num- 
ber of specimens displayed is about 70,000, subdivided as fol- 
lows : Paleontological specimens 25,000, mineralogical specimens 
15,000, economic specimens 20,000, miscellaneous 10,000. En- 
tering the Department from the West Court the visitor will 
find the alcove and first six halls devoted to paleontology. 
Alcove 103. Halls 33, 35, 36, 59, 60, and 61. 
PALEONTOLOGY. 
In the Division of Paleontology it is sought to illustrate by 
fossils or by casts and models of these, the animal and vegetable 
forms which have characterized the life of the globe at the suc- 
cessive stages of its history. The arrangement is primarily 
chronological and secondarily zoological. Advancing from hall 
to hall the visitor sees the development of life upon the earth 
illustrated in the same order in which it occurred in Nature. 
Thus in the first hall of the series. Hall 33, are to be seen the 
fossils of the earliest era of the earth’s history, the Paleozoic; 
in the next three halls, Halls 35, 36 and 59, those of the middle 
era or Mesozoic; and in the remaining three halls. Halls 59, 
60, and 61, the fossils of the Cenozoic or recent era. Within 
each hall, so far as is possible, the fossils of each period are 
arranged so that those of the earliest period shall come first, 
then those of the next succeeding age, and so on. Within each 
period, however, the specimens are arranged in accordance with 
their zoological rank, beginning with the lowest. Fossil plants. 
