Hall 37: Frederick J. V. Skiff Hall. Ores, Marbles, Alka- 
lies. — This hall contains ores of the precious and base metals, 
marbles and building stones and various non-metallic minerals 
which are used for abrasive, refractory and numerous other 
industrial purposes. Beginning at the east end of the hall, 
there are shown, first, synoptic collections of gold, silver and 
lead ores, then collections of these ores geographically ar- 
ranged. Following these are ores of the other metals simi- 
larly disposed. Instructive models illustrating methods of 
mining and extracting the metals from the ores are inter- 
spersed am.ong these exhibits, as are also illustrations of 
some metallurgical processes. The collection of marbles is 
remarkable for its completeness and the large size of the 
specimens, thus enabling the characteristic colors and pat- 
terns of each variety to be seen. A number of varieties of 
building stones from a wide range of localities are shown 
and the exhibit of non-metallic minerals and their products 
presents many interesting features. 
Hall 38: Historical Geology. — The collections illustrate 
historical geology and paleontology and are so arranged 
that, beginning at the south end of the hall, the forms of 
life which have characterized successive stages of the earth’s 
history are illustrated in order from the earliest up to recent 
times. Thus the fossils which represent the life forms of 
each geological period may be found in the portion of the 
hall corresponding in position to that period in time. Begin- 
ning with two introductory cases, one, illustrating methods 
of fossilization, and the other, comparisons of ancient and 
modern plants and animals, the fossils of the Age of Inverte- 
brates, Age of Fishes, Age of Reptiles, Age of Mammals 
and Age of Man are shown successively. Especially note- 
worthy exhibits include a partial skeleton of the huge dino- 
saur, Apatosaurus, from Colorado, a very large skull of the 
hooded dinosaur, Triceratops, a mounted skeleton of the 
extinct ungulate. Allops, shown partially imbedded, complete 
skeletons of the Mastodon, Cave Bear and Irish Deer, and 
several skeletons or parts of skeletons from the asphalt beds 
of Los Angeles, California. 
DEPARTMENT OF ZOOLOGY 
Halls 13, 15-22, First Floor 
Hall 13: George M. Pullman Hall. Horned and Hoofed 
Mammals. — This hall, running north and south and imme- 
diately west of Stanley Field Hall, is devoted to horned and 
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