HATCHER: OSTEOLOGY OF HAPLOCANTHOSAURUS 63 
in a layer of arenaceous shales there occurs a bed of Unios from which were obtained 
most of the species described by Dr. C. A. White as coming from this locality, while 
the shales underlying the thick stratum of sandstone seen at the top of the escarp- 
ment forming the cafon wall just to the left and in front of the tent contains 
numerous small lenses of impure limestone filled with the silicified remains of 
fresh-water gasteropods and the stems and seeds of small aquatic plants apparently 
pertaining to some species of Chara. These limestone lenses are especially abund- 
ant and quite fossiliferous at the locality marked C in the photograph and at a point 
on the same horizon of this talus-covered slope a few rods in front of the extreme 
foreground of the photograph and therefore not shown in the picture. The line of 
trees just above and in front of the Marsh quarry marks the crest of the narrow 
ridge that at this point separates the dry cafion in the middle of the picture from 
Fie. 25. View of Atlantosaurus beds at entrance to Garden Park, eight miles northeast of Canyon City, 
Colorado. From a photograph by Dr. E. H. Barbour. 
Oil Creek on the extreme left. At this point this ridge is about 100 yards in width 
from the brink of the cliff overlooking the bed of the creek and that of the dry 
cafion. In the wall facing Oil Creek at the same horizon at which the bones occur 
in such abundance at the adjacent quarry, dinosaur bones may be seen imbedded in 
similar sandstones, showing that the bone-bearing horizon extends quite through 
the ridge. From the great abundance in which the bones were found up to the 
limits of the quarry as last worked and as shown in the accompanying diagrams, it 
is only reasonable to suppose that many rare treasures await the explorer who has 
the courage and funds necessary to remoye the 15 to 40 feet of sandstones and shales 
beneath which they now le buried. 
7 
The isolated butte known as ‘‘Cottage Rock” seen at the head of the dry canon 
in the middle background is capped with some fifty to one hundred feet of light- 
