12 



the models and plaster casts were ordered by the Trustees to be made, and their 

 articulation was confided to Mr. Flower. 



The result is the exhibition in our National Museum of the entire skeleton of the 

 Megatherium, Plate I., in a much more complete state, and, I believe I may add, 

 more natural attitude, than that of the same extraordinary quadruped, which 

 previously had been unique and the glory of the Royal Museum of Natural History 

 at Madrid. 



For the full fruition by comparative anatomists and palaeontologists of so rich an 

 accession to our evidences of one of the strangest animals of a former world, there still 

 remained one condition, — viz. the power to employ a competent artist to depict the 

 skeleton and its several parts. There could be no question that the opportunity of 

 supplying the omissions, correcting the errors, and clearing up the doubts, in the 

 descriptions founded on the Madrid skeleton, ought to be embraced without loss of 

 time. The enlightened and liberal grant of £1000, placed by Lord John Russell, 

 then Prime Minister, at the disposal of the Council of the Royal Society, in aid of the 

 labours of men of science, seemed to me to afford the means of removing the only 

 difficulty that stood in the way of completing the object of my wishes. I therefore 

 submitted the case to the "Committee of Recommendations for the application of 

 the Government Grant," and the Council of the Royal Society was pleased to 

 approve the recommendation of the Committee, viz. "that £100 be granted to Pro- 

 fessor Owen, to be applied to the procurement of drawings of the undescribed and 

 unfigured or inaccurately figured parts of the skeleton of the Megatherium." 



The present memoir, and its illustrations from the accurate pencil of Mr. Joseph 

 Dinkel, are the result of that recommendation ; and I have only to add, that the 

 descriptions and figures of the several parts of the skeleton of the Megatherium, now 

 in London, have been taken from the actual bones ; and the views of the entire 

 skeleton from the articulated casts, which are so beautifully exact, as, for all the 

 essential purposes of science, to be of the same value and utility as the bones them- 

 selves would be if so articulated together. 



^ 2. Of the Spinal Column. 



The skeleton of the Megatherium, like that of all other vertebrate animals, being 

 composed of a series of segments, similar in their composition, and referable under 

 all their modifications to a common type, answering to that which is figured as the 

 ' typical vertebra' in my work on the Vertebrate Skeleton*, I shall commence its 

 description by one of those segments which deviate least from the archetypal cha- 

 racter ; and such segments we find to constitute the major part of the trunk, where 

 they form what, in human anatomy, would be termed ' dorsal vertebrae,' ' ribs,' ' car- 

 tilages of ribs' and ' sternal bones.' 



* On the Archetype and Homologies of the Vertebrate Skeleton, 8vo, 1848, p. 81, fig. 16, and p. 82, 

 fig. 15. 



