74 Saurians of the Dakota Beds of Colorado, | February, 
tile I described in my paleontological bulletin No. 26, under the 
name of Camarasaurus supremus. Subsequent sendings included , 
many of the more important bones of the skeleton, which render 
Fig. 4. Fig. 3. 
m Fig. 3—Dorsal vertebra represented in Fig. 1, the right sight side. Fig. 4—A 
caudal vertebra viewed from behind. 
it comparatively easy to determine the general character of this 
monster. Later collections received from Mr. Lucas include the 
teeth of two large species of a new genus which has been charac $ 
terized under the name of Caulodon ; and the vertebrze of tw a . 
genera new to science, which I have named Tichosteus and Sym- | 
Phyrophus. He also procured remains of two additional forms of 
new genus Amphicelias. A species. of tortoise was associated 
with these saurians, and appears to have been abundant. It is — 
the oldest species of the order yet obtained from American for — 
mations, and is not very different from existing forms. 
_ The species of Camarasaurus and Amphicelias, which attained to 
the most gigantic proportions, are remarkable for the light con- 
struction of the vertebrz anterior to the tail. In both gener 
