350 Rev. H. N. Hutchinson— ^-Observations on 



Tyrrell (G. W.). 1909. "The Classification of the Post-Carboniferous 



Intrusive Igneous Kocks of the West of Scotland" : Trans. Geol. Soc. 



Glasgow, vol. xiii, pt. iii, pp. 298-317. 

 1913. "The Petrology of Arran. 2. Crinanite of Whiting Bay": 



Geol. Mag. (V), Vol. X, pp. 305-9. 

 1916. "The Petrography of Arran. 3. Pitchstone Xenoliths in Basalt 



Dyke, Dippin " : Geol. Mag. (VI), Vol. Ill, pp. 193-6. 

 1917. "The Igneous Geology of the Cumbraes " : Trans. Geol. Soc. 



Glasgow, vol. xvi, pt. ii. 



IV. — Observations on the Peconstructed Skeleton of the Dino- 

 saurian Reptile Diplodocus Carnegiei as set up by Dr. W. J. 

 Holland in the Natural History Museum in London, and an 

 attempt to restore it by means of a Model. 



(PLATES XXII AND XXIII.) 



By the Bev. H. N. Hutchinson, M.A., F.E.G.S., F.G.S., F.Z.S., etc. 



N the following pages trie writer has endeavoured to consider this 



I 



skeleton in a common-sense way, and to arrange the limbs with 

 reference to ordinary mechanical principles, and also by comparison 

 of the bones with those of different mammalian and reptilian types. 

 A good many years ago, Von Meyer was so struck by the colossal 

 and rather straight hind-limb bones of the Dinosauria and their 

 superficial resemblance to those of elephants, that he proposed the 

 term Elephantopoda ; but at that time the group had not been 

 classified by Marsh and others into distinct sub-orders, with very 

 different limbs. 



The writer maintains that Dr. W. J. Holland, 1 Professor Osborn, 3 

 Dr. Marsh, Hatcher, 3 and others who are responsible for the 

 present reconstruction (see Plate XXII) have been, perhaps 

 unconsciously, influenced by Yon Meyer's interpretation, and 

 consequently were somewhat too anxious to produce something 

 very big and imposing. He has endeavoured to give a more 

 natural interpretation of this skeleton, and to bring it more into 

 harmony with other types of reptiles. The restorations by Tornier 

 and Holland are given in the American Naturalist, vol. xliv, 1910. 



Before proceeding to discuss the details of this colossal skeleton, 

 81 feet long or more, it will be convenient briefly to summarize the 

 broad conclusions which have been arrived at. 



1. "With regard to the general pose of the skeleton. There are 

 grave reasons for considering that it stands too high. 



2. The limbs, instead of being placed in a vertical plane, should 

 be inclined at an angle to the body, somewhat as we see in 

 lizards and crocodiles. Such an arrangement involves bringing 

 down the vertebral column into a lower position, such that the 



1 W. J. Holland, Memoirs of the Carnegie Museum, vol. ii, No. 6, The 

 Osteology of Diplodocus, Marsh. 



2 " A Review of some recent criticisms of the restorations of Sauropod 

 Dinosaurs existing in the Museums of the United States, with special reference 

 to that of Diplodocus Carnegiei in the Carnegie Museum ' ' : American 

 Naturalist, vol. xliv, May, 1910. 



3 Dr. J. B. Hatcher, Memoirs of the Carnegie Museum, vols, i and ii. 



