REVIEW OE THE CHARACTERISTICS OF THE VERTE¬ 
BRATE FAUNA OF THE WASATCH EOCENE OF 
NEW MEXICO. 
In the preceding pages, the species described are related in the 
following manner: 
Mammalia. 
Pefissodactyla.. 
Amblypoda .... 
Pantodonta . 
In cert® sedis... 
Bunotheria. 
Creodonta .. 
Mesodonta.. 
f Insectivora 
Tceniodonta . 
Eodentia. 
Aves.— 
Eeptilia. 
Crocodilia. 
Testudinata .... 
Lacertilia. 
Pisces. 
Giuglymodi .... 
Plagiostomi .... 
8 
13 
11 
2 
4 
10 
8 
3 
30 
3 
1 
24 
6 
16 
2 
8 
2 
6 
This total number of eighty-seven species may be considered in two 
aspects, viz, in regard to their geological position, and their anatomical 
structure. 
I. The geological horizon of the Wasatch beds .—The record preserved 
in these beds is doubtless more imperfect than that found in many others, 
owing to various physical conditions. One of these is an evident disturb¬ 
ance of temperature and moisture, which they have sustained perhaps in 
connection with the volcanic phenomena which played so important a part 
in New Mexico during later Tertiary times. The fossils are generally found 
269 
