Article VI.— A COMPLETE SKELETON OF CORY- 

 PHODON RADIANS. NOTES UPON THE LOCO- 

 MOTION OF THIS ANIMAL. 



By Henry Fairfield Osborn. 

 Plate X. 



The chief object of the writer in planning the American 

 Museum Expedition of 1896 was to complete materials for the 

 investigation of the evolution of the Amblypoda, and extend our 

 knowledge of Coryp/iodon. The observations of Cope, Marsh, 

 Osborn, Wortman and Earle have been principally upon scattered 

 and imperfect material, and it seemed of the utmost importance 

 to secure materials sufificient to determine the relations of this 

 animal to its ancestral form, Fantolambda, and to its successive 

 form, Uiiitathoiuin ; also the proportions of the body, the posi- 

 tions of its limbs and the number of its vertebrae. Accordingly 

 our party, led by Dr. Wortman, aided by Mr. Granger of the 

 Museum, and Messrs. Brown and Riggs of the University of Kan- 

 sas, spent the months of April and May in northwestern New 

 Mexico, revisiting the locality where Cope's most complete Coiy- 

 phodon, C. elephantopiis, had been found. The search here in the 

 ' Coryphodon ' or ' Wasatch Beds ' was entirely unsuccessful, but 

 fortunately the underlying ' Torrejon Beds ' yielded a remarkably 

 complete series of Pantolambda. The party moved to the north 

 in June, and devoted July and August to a most energetic explo- 

 ration of the Big Horn Basin, especially of the exposures on the 

 south side of the Gray Bull River from Brown's Ranch towards 

 the Big Horn River below Otto. 



The party soon discovered two skulls, both in the sandstone. 

 The first (No. 2867), upon level A, with four vertebrae and some 

 fragments of limb bones associated with it, the teeth being badly 



X^March, i8gS.\ L^i] 6' 



