HELL CREEK BEDS, CERATOPS BEDS AND EQUIVALENTS 185 



between the Grand and Moreau Rivers, South Dakota^ and Converse 

 County, Wyoming. 



The fauna of the "Hell Creek beds" is a comparatively rich one, 

 comprising a few mammals, numerous dinosaurs belonging to the 

 families Ceratopsidos, Trachodontida?, etc., together with crocodi- 

 leans, turtles, scales and vertebras of fishes, and some thirty species of 

 invertebrates, mainly Unios. On the basis of the identity of many 

 genera and species of both vertebrates and invertebrates, as well 

 as on the striking lithologic similarity, the "Hell Creek beds" of 

 Montana are correlated by Brown with the "Ceratops beds" of 

 Converse County, Wyoming, a correlation confirmed by Hatcher 

 and Lull in the recently published monograph of the Ceratopsia.' 



Up to the time of the publication of Brown's paper (1907), but 

 few fossil plants had been found in the " Hell Creek beds, " and these 

 in only the upper member. Dr. Arthur Hollick, to whom they 

 were submitted, identified Equisetum lavigaium Lesq., Rhamnus 

 salicifolius Lesq., Ficus spedahilis Lesq., Pterospermites sp., Sequoia 

 heerii Lesq., and a mass of seeds resembling Sahalites friictifer 

 Lesq. To these I was able to add a peculiar undescribed Ficus fruit, 

 which has also been found in Converse County and at Forsyth. In 

 the past season, however, Mr. Brown was fortunate in securing a 

 fine collection of leaves in direct association with the skeleton of a 

 dinosaur. This collection, which he has kindly permitted me to 

 study, embraces the following species: 



Big Dry Creek, 60 miles south of Glasgow, Montana. Clays between 

 middle and basal sandstones and in association with skeleton of 

 a dinosaur. 

 Sequoia nordenskinldi Heer. 

 Taxodium occidenlale Newb. 

 Ginkgo adiantoides (Ung.) Heer. 

 Populus cimeata Newb. 

 Populus amblyrhyncha Ward. 

 Qucrcus sp. (Same as at Glendive.) 

 Ficus artocarpoides Lesq. 

 Sapifidus affinis Newb. 

 East side of Big Muddy Creek, 28 miles south of Lisner, Montana. 250 

 feet above Fox Hills. 

 Sequoia heerii Lesq. 



' Todd, Am. Geol., vol. 17, 1896, pp. 347-349. 

 * Mon. U. S. Geol. Surv., No. 49, 1907, p. 1S4. 



