i 
: 1378. | Saurians of the Dakota Beds of Colorado. 73 
It was therefore a source of no small gratification to have been 
in receipt of letters from Superintendent O. W. Lucas, of Canyon 
City, and Professor Arthur Lakes, of Morrison (both in Colorado 
and one hundred miles apart), at about the same time, informing 
me of their simultaneous discoveries of vertebrate remains in the 
_ beds of Dakota age, near their respective residences. The bones 
_ obtained by the former were found in a rather friable bed, and 
were easily extracted in good condition. Some of those obtained 
by the latter gentlemen were from a similar or identical formation, 
Fig. 2—Anterior dorsal vertebra of amarasi us supremus from behind. 
while others were embedded in the hard sandstone already men- 
_ tioned. I obtained possession of those from near Canyon city, 
_ while those from near a were purchased for the museum of 
‘Yale college. 
One of the first objects sent by Mr. Lucas is a fragmentary lower 
jaw of a carnivorous dinosaurian, which he found on the surface 
of the ground. This fossil was found to belong to a species here- 
_tofore unknown, which I referred to the genus Lae/aps, under the 
name of Laelaps trihedrodon} The second sending included a num- 
ber of vertebrz, which apparently represent a much more gigantic 
animal, and I believe the largest or most bulky animal capable of _ 
_ progression on land, of which we have any knowledge. This cae | 
: * Bullet. U. S. Geol. Surv. Terrs. ILI, 1877, p. 805. 
