No. 502] HABITS OF SAUBOPODOUS D1NOSAUBS 677 



centra where the fin is supposed to have been situated 

 seems to have been slight, and the neural spines are not 

 higher than elsewhere. The present writer finds neither 

 in the feet nor in the tail any special arrangements for 

 swimming. For navigation in its restricted waters no 

 fin was needed. Almost any colubrid snake makes fair 

 progress in the water, notwithstanding the absence both 

 of a compressed tail and of a vertical fin. 



Hatcher's final view does not, after all, appear to have 

 been greatly different from that of Osborn. He held that 

 Diplodocus, as well as most of the Sauropoda, were essen- 

 tially terrestrial animals, but that they passed much, 

 perhaps most, of their time in shallow water, where they 

 could wade about and search for food. He believed that 

 they were ambulatory, but quite capable of swimming. 

 Hatcher's language does not necessarily imply that these 

 animals walked about after the fashion of quadrupedal 

 mammals, but his restorations show plainly that such was 

 his conception. 



This conception has prevailed in the plaster reproduc- 

 tions of the skeleton of Diplodocus which have been sent 

 abroad by the Carnegie Museum and set up in London, 

 Berlin and Paris; and in the small plaster restorations 

 issued by the American Museum of Natural History. 

 However, the limit of quadrupedal erectness, rigidity, 

 rectangularity, and rectilinearity has quite been reached 

 in the skeleton sent by the last mentioned institution to 

 the Senckenberg Museum, at Frankfort-on-the-Main. In 

 this case the poor beast is made to stand straight-legged 

 and almost on the tips of its digits. On the other hand, 

 the American Museum's skeleton of Brontosaurus, a 

 much larger and heavier reptile and one sorely needing 

 the mechanical advantage of straight legs, in case it had 

 to bear its body free from the ground, has been presented 

 to the modern world as having been decidedly bow-legged. 



To the present writer it appears that the mammal-like 

 pose attributed to the Sauropoda is one that is not re- 

 quired by their anatomy and one that is improbable. 



