8 SMITHSONIAN INSTITUTION 



Leaving Torrington, we worked in succession in the vicinity of 

 Bridgeport and Crawford in Nebraska, Pine Ridge and Scenic in 

 South Dakota, and Lusk and Douglas in Wyoming. A few days to a 

 few weeks were spent in each of these localities with varying success, 

 although material was collected from every place visited. 



The hulk of the material collected is from the upper or Oreodon 

 beds of the ( )ligocene, although a few specimens were obtained from 

 the Titanotherium beds and from the Miocene formation. Among 

 specimens worthy of special mention is the skeleton of a hawklike 

 bird having the skull and lower jaws present, undoubtedly the most 

 complete bird specimen ever found in the Oligocene of North 

 America; a skull and partial skeleton of Eusmilus, a rare saber- 

 toothed cat ; two articulated skeletons of Mesohippus; two articulated 

 skeletons of Mcrycoidodon, and one each of Lcptouicryx, a small deer- 

 like animal, and Ischromys, a large squirrel. Several of the forms ac- 

 quired were previously unrepresented in the collection, and it is prob- 

 able that some new to science will be found when a critical study is 

 made. In all, the collections filled 17 large boxes having a combined 

 weight of 4,865 pounds. 



A novel feature of the expedition was the finding of numerous 

 turtle skulls. The most common and widely distributed fossil of the 

 Oligocene faunas is the land tortoise described by Leidy as Stylemys 

 nebrascensis. Its fossil remains are found scattered throughout the 

 middle and upper Oligocene, in many places in profuse abundance. 

 Skulls, however, are rarely found, and for this reason a systematic 

 search was made in and around the many weathered shells encountered, 

 with the result that 15 skulls were recovered, the study of which will 

 furnish a most interesting contribution to our knowledge of the 

 turtle's skeletal anatomy. 



The Mauvaise Terre of the early French-Canadian trappers and 

 explorers has long been classic ground for those collecting the fossil 

 remains of Oligocene animals, but the somewhat prevalent idea that 

 its fossil treasures will be exhausted by continuous collecting, seems to 

 be refuted by our experience of the past summer. Several areas in 

 which we worked both in the big badlands and elsewhere had been ex- 

 plored for many seasons, some as late as the year before, and yet speci- 

 mens were, found at every locality visited, in almost any field where 

 fossils occur, dogged persistence will be rewarded. The relatively 

 rapid erosion of these beds is constantly exposing fossils to view, and 

 so long as this continues there will never be a dearth of specimens. 



I was fortunate again in securing the services of George F. Stern- 

 berg and M. V. Walker as field assistants, and the successful outcome 

 of the expedition was in large part due to their intelligent and hearty 

 cooperation. 



