218 GEOLOGY OF THE DENVER BASIN. 



A few fossil plants occur, but those found thus far are poorly preserved, 

 and the only identifiable species collected is Magnolia tenuinervis Lx., a com- 

 mon Denver bed species originally described from Table Mountain. No 

 invertebrate fossils have been found as yet, but it seems probable that a 

 number of vertebrate species, described by Cope as from the Laramie of the 

 Animas River section, came out of the strata which so closely resemble 

 the Denver formation. 



In an article discussing- the relations of the Puerco and Laramie 

 deposits 1 Professor Cope refers to the succession of beds on the Animas 

 Liver, saying: "According to the observations of Mr. David Baldwin the 

 Laramie beds succeed [the Puerco] downward, conformably it is thought 

 by Mr. Baldwin; and have a thickness of 2.0()() feet at Animas City, New 

 Mexico [Colorado?]. A few fossils sent from time to time by Mr. Baldwin 

 identify the Laramie. This is especially done by the teeth of the dino- 

 saurian genus Dysganus Cope, which is restricted to the Laramie formation 

 elsewhere. Also by the presence of the genera Lselaps and Diclonius, 

 which in like manner do not extend upward into the Puerco beds." 



According to the statement of Professor Cope, made personally to 

 the writer and quoted with his permission, these fossils were collected 

 incidentally to the investigation of the Puerco fauna and for the purpose 

 of identifying the underlying formation. lie believes it most probable 

 that they came from what are here called the Animas beds, which extend 

 for several hundred feet below the Puerco. Professor Cope now regards 

 the Dysganus and Diclonius as closely allied to the horned dinosaurs 

 (( ieratopsidse Marsh, Agathaumuhv ( 'ope), which, as will be shown, form the 

 most characteristic element of the vertebrate fauna known in the Arapahoe 

 and Denver beds. 



The Animas beds, as this post-Laramie formation may be called, are 

 to be regarded as a most direct equivalent of the Denver beds, identical in 

 peculiar lithologic character, lying between typical Laramie and Puerco, 

 and containing fossils winch, so far as known, indicate a similar fauna and 

 flora. This occurrence on the border of Colorado and New Mexico, and 

 south of the San Juan Mountains, is evidence of the great importance 



; An.. Naturalist, Vol. XIX. 1885, p. 985. 



