THE HALL OF FOSSIL VERTEBRATES 
viving relatives and the habits of life for which the animals seem 
to have been fitted. The general proportions of the animal, the 
outlines and form of head and body and, to a great extent, the 
expression of the features are usually accurately known from 
the fossil skeleton. The nature of the skin is sometimes but not 
often certainly known, and the coloring is always conjectural, 
the paleontologist and the artist having been guided by the col- 
oring of living relatives and the supposed habits of the animal. 
The Window Transparencies are enlargements from photo- 
graphs of the regions where the fossils occur, and generally show 
the localities where unusually fine specimens in this hall were 
found. The Expeditions sent out yearly to the Fossil Fields 
carry with them a photographic outfit, and several hundred 
characteristic views have been taken, from which these have 
been selected. The Pillar Cards and general Labels in the cases 
give detailed information about each group of fossils. One of the 
cases in the centre of the middle aisle illustrates the method by 
which the fossils are collected and conveyed to the Museum. 
The Charts at each side of the entrance show the order in which 
the rock-strata lie, one over another, and the kinds of fossils 
found in each stratum. 
