Department of Geology, 
The collections of this Department illustrate the subject of 
geology and its subdivisions, chief among which are paleontol- 
ogy, mineralogy, economic geology, and geographic geology. 
The collections are grouped so as to represent these subdivisions 
separately while they also form a comprehensive whole. The 
collections occupy three halls of the main building and the 
entire west wing. The total number of specimens displayed is 
about 65,000, subdivided as follows: Paleontological specimens 
25.000, mineralogical specimens 10,000, economic specimens 
20.000, miscellaneous 10,000. Entering 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, 
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