522 E. H. Barbour — Nev: Longirostral Mastodon. 



Art. XXX V. — A New Longirostral Mastodon from Ne- 

 braska, Tetrabelodon osborni, sj). nov. • by Eewin H. 

 Barbour. 



The Nebraska State Museum was enriched during the field 

 season of 1915 by an abundant and varied mammalian fauna 

 from the fossil fields of Northern Nebraska. Much of this 

 has an added interest because new. However, the collection 

 of proboscidean bones seems to challenge first attention. Con- 

 siderable Tetrabelodon material was secured, notably several 

 fine jaws, two of which are probably new, one undoubtedly so. 

 The latter, or the Boyd County Tetrabelodon, constitutes the 

 basis of this paper. 



The spring and summer of 1915 were characterized by 

 unusual precipitation. Running water gullied a pasture belong- 

 ing to Mr. Z. T. Long, 7 miles north and 2 miles east of Bris- 

 tow, Nebraska, and exposed a Tetrabelodon. After making 

 extensive excavations in the hope of securing this specimen, 

 Mr. Long recognized the futility of the undertaking, promptly 

 buried the exposed bones, and set up a barricade to ward off 

 herds. Appreciating the scientific value of the specimen, he 

 had notice sent, late in June, to the University of Nebraska. 

 Many similar skeletons have been found in the State but prac- 

 tically all of them have been destroyed before notice was 

 given. 



In company with Mr. C. Harold Eaton, the writer visited 

 Bristow at once, and in less than a fortnight, the skeleton of a 

 new Tetrabelodon, practically complete, was secured. The 

 skeleton was exposed on a sloping hillside in channel gravels 

 composed of three or four feet of very coarse, lime pebbles 

 underlain by five or six feet of fine sand. The deposit is of 

 Pliocene age equivalent to the Snake River of Cherry County, 

 and the lower Devil's Gulch beds of Brown County. For 

 convenience we shall call these the Bristow beds. 



The skull and mandible, though checked and fragile, were 

 finely preserved, and one fore-limb had all of its elements, 

 from scapula to manus inclusive, in position. The skull, man- 

 dible ancl hyoids, pelvis, scapula?, and numerous ribs were close 

 to the surface. Consequently they were checked to the extreme 

 degree, and rootlets had found their way into the bones. It 

 required extreme care in collecting to save this specimen. 

 Certain bones, at a depth of three to seven feet, were harder 

 and less checked. 



"Without waiting for the preparation of the skull and skele- 

 tal parts, it seems expedient to figure and briefly describe the 

 mandible. 



