64 
PALEONTOLOGICAL GEOLOGY 
been done there will be disclosed planes of unconformity between 
the Ludlow shales and the Cannonball shales and also, farther to 
the west, between the Ludlow shales and the Union beds, as well 
as between the Cannonball shales and the Union formation. The 
relationship of the several terranes are indicated in the annexed 
diagram. 
The vertebrate paleontologists would draw the basal line of the 
Tertiary at the horizon of the upper unconformity. The inverte¬ 
brate authorities prefer the same boundaries. Paleobotanists find 
the floral remains identical throughout the interval between the 
two unconformities. The stratigraphers, backed by ample and 
what seems to be decisive diastrophic data, regard the lower un¬ 
conformity plane as the major break in sedimentation and one of 
very wide extent. The conflicting lines of evidence make the pro¬ 
blem involved one of the most interesting stratigraphic questions 
on the continent today. Ki:y^s. 
Affinities of the Cannonball Fauna. The organic remains con¬ 
tained in the Cannonball formation with the exception of five 
brackish-water types, are strictly marine forms and include 2 
species of foraminifers, 6 of corals, 60 mollusks, and 2 sharks. 
Notwithstanding the fact that the molluscan forms have a modern 
aspect on account of the absence of the ammonoids and other dis¬ 
tinctively Mesozoic types they are connected with preceding Late 
Cretacic faunas of the same region by the specific identity of no 
less than 40 percent of the species. No strictly Eocene species are 
