The Diplodocus 



a 



Fig. 2. a, b, Two caudal 

 vertebras of Diplodocus; c. 

 chevrons on under side of 

 tail. 



discovered beast was the fact that on the lower side 

 of the tail of the animal, where the vertebras come 

 together, there are little bones known to anatomists as 

 chevrons, which in the case of these particular animals 

 look like little rafters, and which are arranged in pairs. 

 This arrangement, it has 

 since been discovered, is not 

 altogether peculiar to the 

 species of the genus Diplo- 

 docus, but occurs in other al- 

 lied dinosaurs; nevertheless, 

 the name having been orig- 

 inally given to this form, 

 according to the laws of 

 scientific nomenclature it 



cannot be changed. Professor Marsh obtained 

 through his assistants, principally through the labors 

 of Dr. S. W. Williston, now the Professor of Paleon- 

 tology in the University of Chicago, some of the limb- 

 bones, two somewhat fragmentary skulls, various 

 vertebras, and other parts of the animal, sufficient to 

 enable him to form an approximate idea of what it 

 may have been like. The question of its form and 

 structure was nevertheless left for want of more 

 material in a somewhat uncertain state. Subsequently 

 Professor Henry Fairfield Osborn obtained a pelvis 

 and the greater part of the tail of a diplodocus, and 

 published a paper enlarging our knowledge of the 

 framework of the animal. 



Shortly after the death of Professor Marsh, Mr. 

 Andrew Carnegie expressed to the writer his wish that 

 the Museum of the Institute which he had founded in 

 Pittsburgh should undertake the task of prosecuting 

 scientific researches along the same lines which had 



