horizons or vi:i;ti:i;i;ati: fossils. 477 



need not be further mentioned here. The next higher horizon of special 

 importance, which the writer has earned the Pteranodon beds, from the 

 gigantic pterodactyls tumid in them, is very rich in vertebrate fossils, and 

 among these remains of marine swimming reptiles are most abundant. 

 Here, too, were found the well-known birds with teeth. In the Denver 

 Basin vertebrate fossils from this horizon have not Keen seen in place, 

 although isolated specimens have been found. In the foothills to the north 

 interesting discoveries have been made, one locality being on Lodge Pole 

 ("reek, Wyoming. On the plains farther east the Pteranodon beds have a 

 »-re;it development, especially in Kansas along the Solomon, Saline, and 

 .Smoky Hill rivers, where the variegated chalk bluffs are rich in vertebrate 

 fossils. To the south the\ may lie seen ;it various points nearer tin- moun- 

 tains, particularly in the vicinity of Pueblo and Canyon. The Pteranodon 

 beds are in part the equivalent of No. .';. Meek and Bayden. The next 

 horizon given in the section, fig. 23. is that of the .Montana group, which 

 is well represented in the Denver Basin, but its vertebrate fossils do not 



call for special mention here. Farther north in Wyoming the Fox Hills 



section of this group lies directly beneath the Ceratops beds, the horizon 



next to he considered. 



( BRATOP8 Bl I'-. 



The Ceratops beds placed next in the section are o'f special importance. 

 from the remarkable fossils the) contain and their greal development in the 

 north. They form one of the most distinct vertebrate horizons in this 

 country. In the number and variety of their vertebrate fossils they are 

 surpassed only by the Atlantosaurus beds, and as both horizons are so well 

 developed in the Denver Basin special attention will he given in this chap- 

 ter to the animals entombed in each of them. The exact relation of the 

 Ceratops beds to the adjoining deposits in the vicinity of Denver will not 

 here lie discussed, but it is worthy of notice that, to the north, beds con- 

 taining the same fauna have a remarkable extension, mainly as lacustrine 

 shales and sandstones. 



The most characteristic development of the Ceratops beds known to the 

 writer from personal observation is in the northeastern part of Converse 

 County. Wyoming, in the region represented in the accompanying map, 



