the Skeleton of Diplodoeus Camegiei. 357 



abdominal surface will rest not very far above the ground. The 

 writer has constructed a model 4 feet long in plasticine. Plate XXIII 

 is from a photograph of a plaster cast from this model, which may now 

 be seen in the British Museum (Natural History), Cromwell Road, 

 8.W. It is in the Reptile Room, and under the Diplodoeus Skeleton. 



3. That Diplodoeus was, in habit, partly aquatic and partly 

 terrestrial. 



From Plate XXIII the reader will see the position that has been 

 chosen for this restoration. The tail mostly rests on the ground and 

 the body is horizontal, while the long neck has a slight and graceful 

 curve upward. A long, narrow ridge is shown on the back, which 

 gradually rises upward from the shoulders to the lumbar region. 

 The writer thinks he is justified in making this ridge, because 

 a ridge exists in many recent reptilian types, though of course such 

 appendages depend largely upon climate, etc. Lizards inhabiting 

 sandy deserts show a profusion of spines, scales, etc., which evidently 

 are protective. Even plants show a similar tendency to avoid the 

 chances of being devoured by hungry mammals. But we must not 

 assume such conditions existed, and so have dispensed with all 

 appendages of that kind. 



The limbs should be quite free from the body ; and any attempt to 

 place the femur within the body of Diplodoeus as if it were a mammal 

 would be a fatal mistake. Dr. "W. J. Holland has ventured to do so 

 (see his restored skeleton in the Natural History Museum and 

 Plate XXII). 



But such interpretation is not borne out by the shape and general 

 plan of the femur. The writer contends that to place the limb bones 

 in an upright position, as in the skeleton now under consideration 

 (and in the restorations of Marsh, Hatcher, Osborn, and others), is 

 not consistent with the position of Diplodoeus in the animal kingdom. 

 For, after all, it is a reptile. There is no getting away from that 

 fact : and therefore we must beware of the temptation to give any 

 appearance of usurping chai'acters that properly belong to the mam- 

 malian class. But on the other hand, to say that it is a reptile does 

 not necessarily imply a belief that it crawled low down like a lizard 

 or a crocodile. The somewhat grotesque arrangement of the skeleton 

 shown in Dr. Tornier's restoration is based on that view, and the 

 result is obviously an impossible interpretation. Nor can the writer 

 see his way to accept the view that Diplodoeus walked in the sense 

 in which we apply that expression as to the mode of progression seen 

 in big mammals such as the elephant and rhinoceros. 



According to Yon Zittel, the Sauropoda display closer relationships 

 with Crocodilians than do the other orders of Dinosaurs, and share 

 a number of features in common with the Parasuchia (Belodon, etc.). 

 This important conclusion by such an authority must be borne in 

 mind in considering Diplodoeus. Hence the writer feels justified 

 in dealing with the femur of Diplodoeus, largely by comparison with 

 that of the crocodile. 



We must try to picture something between crawling and walking, 

 as expressed by our restored model. The relatively small size of the 

 pelvic girdle is, of itself, enough to remind us that, in trying to 



