Part of the botanical collections are exhibited in the gallcry
 of plants on the second floor, in the southwestern corner of
the museum. The Herbarium, in the mezzanine, contain
150,000 species of plants systematically arranged and ready
for consultation by students. It is one of the largest herbaria
 in North America.
The mineralogical collections are exhibited on the first
floor inthe Gallery of Geology and Mineralogy. The reserved
collections are on the third floor. The minerals include the
celebrated Jefferis Collection purchased by Mr. Carnegie.
This collection contains many specimens orginally figured in
Dana’s “Mineralogy.” One of the exhibits in this gallery is
the group of stalactites and stalagmites obtained at Naginey,
Pennsylvania.
The paleontological collections are among the most extensive,
 beautiful, and famous in the world. The mounted
vertebrates are on the first floor. The invertebrates are on
the second floor.
The collections include the great Bayet Collection, containing
 120,000 specimens, being the largest and best collection
 representing the fossil fauna of Europe to be found in the
New World. It has been said that “to study the mammals of
the Miocene and the reptiles of the Jurassic one must visit
Pittsburgh.” Among the striking objects are the skeletons of
Camarasaurus in the matrix, found in the National Dinosaur
Monument in Utah, of Apatosaurus louisae named in honor
of Mrs. Carnegie, and of Diplodocus carnegiei, named in
honor of Mr. Carnegie. Copies of the latter have been
presented to the National Museums of England, France.
Germany, Russia, Austria, Italy, Spain, and Argentina.
Portions of these collections are placed in the gallery of
avian anatomy already alluded to, and in the gallery of vertebrate
 anatomy, the latter adjoining the gallery of mammals.
 There are thousands of specimens.
The exhibits occupy almost the entire space on the third
floor. Here is the largest collection of Costa Rican antiquities
 in the world. Here are large collections representing
various North American tribes from Alaska to Panama:
collections illustrating the manners and customs of the aboriginal
 people of the South Sea islands and of Africa.