THE AMERICAN NATURALIST [Vol. XLIV 



in which they kept their bodies while the feet were em- 

 ployed for purposes of locomotion along the banks. The 

 Diplorlocits must have moved in a groove or a rut. This 



might perhaps account for his early extinction. It is 

 physically and mentally bad to "get into a rut." 



Assuming that the articulation of the femur after all 

 was not as it is in the lacertilia, and accepting, merely 

 for the sake of argument, the pose of Professor Tornier, 

 who, though contending that the creature was a lacer- 

 tilian— "ein Eidechse"— nevertheless, constrained by 

 obvious difficulties, in his drawings does not give the 

 femur the characteristically lacertilian pose, I have taken 

 pains to place the bones of the replica of the Diplodocus 

 now in course of preparation for the Imperial Academy 

 at St. Petersburg as nearly as is possible in the position 

 which Professor Tornier demands that they should have. 

 I have accepted Tornier 's "richtige SteUting" for the 

 time being, and have collocated the bones in the position 

 which he demands for them, and I have the pleasure 

 herewith of submitting to you photographs of the bones 

 thus located (Figs. 10 and 11). In the first place you 

 will observe that it is beyond possibility, when locating 



