68 
PALEONTOLOGICAL GEOLOGY 
marine Cretacic section and the fresh water Lance deposition. 
The Laramian series is not known within this area. Can it be 
doubted that it is the interval during which in other regions beds 
of Laramian equivalency were laid down and subsequently re¬ 
moved in whole or in part? That there is an important interval 
of some kind is also shown by the fact that it was sufficiently 
long for more than 60 per cent of the marine Cannonball forms 
to be derived through modification from the typical Fox fauna. 
Knowlton. 
Phyletic Relations of Lance Vertebrates. The Lance verte¬ 
brates are strictly Cretacic types. The fauna is clearly a continu¬ 
ation and a specialization of the Judith (Late Cretacic) fauna. 
It contains no new elements. As shown by the amount of evolu¬ 
tionary change in many phyla it is considerably later in point of 
time than the fauna of the Judith and Edmonton beds. 
The earliest placental mammals are at the Puerco horizon, 
which may be as old as the Lance, or older. The true Tertiary 
mammalian fauna appears suddenly at, or near, the bottom of the 
Wasatch section. It is a distinctly new fauna; and consists 
mainly of the modern orders. The great faunal break lies at the 
end of the Paleocene, with the increasing of Cenozoic vertebrates 
at the base of the Wasatch section. 
Of the two leading criteria generally followed in the faunal 
classification of geological terranes first appearance of new groups 
seems more logical and practical than extinction of ancient types. 
By this standard the Wasatch fauna is the introduction of dis¬ 
tinctively modern, or Cenozoic life, the preceding faunas, even 
including the Paleocene placentals being essentially the last ves¬ 
tiges of Mesozoic life. 
When the several lines of biotic evidence are so conflicting 
is it not possible by mutual concession to adopt some compromise ? 
The top of the Union section appears to have best elements of 
mutual acceptance. It is in conformity with the historic and 
common European usage. It conforms to the insistence of the 
paleobotanists that the Lance and Union sections should be kept 
together. It seems to give a satisfactory base for the stratigrapher 
in the wide-spread and characteristic Wasatch formations. It 
places all the dinosaur formations, and the bulk of the “Pale- 
