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X. On Dinornis', an extinct Genus of tridactyle Struthious Birds, with descriptions of 

 portions of the Skeleton of Jive Species which formerly existed in New Zealand. 



By Professor Owen, M.D., F.R.S., Z.S., Sfc. 8fc. (Part I.) 



it 



Communicated November 28th, 1843. 



Introduction. 



L HE brief history of the discovery of the Dinornis, a genus of gigantic terrestrial birds, 

 which appears to have become extinct within the historical period in the North Island 

 of New Zealand, like the Dodo in the island of Mauritius, will be found in the Proceed- 

 ings of the Zoological Society for November 1839, and in the Society's Transactions, 

 vol. iii. p. 32, pi. 3. These papers contain the inferences deduced from the structure 

 of the shaft of a femur, which led to the first announcement of the former existence in 

 New Zealand of a large Struthious bird " of a heavier and more sluggish species than 

 the Ostrich." 



As the full development and confirmation of this idea is included in the following 

 pages, I am induced, in vindication of the fruitful principle of physiological correlations, 

 the value of which as an instrument in the interpretation of organic remains there has 

 been a tendency to depreciate in an otherwise estimable osteological work', to pre- 

 mise the abstract of my former communication published four years ago : — 



" The fragment is the shaft of a femur, with both extremities broken off. The length 

 of the fragment is six inches, and its smallest circumference is five inches and a half. 

 The exterior surface of the bone is not perfectly smooth, but is sculptured with very 

 shallow reticulate indentations ; it also presents several intermuscular ridges. One of 

 these extends down the middle of the anterior surface of the shaft to about one-third 

 from the lower end, where it bifurcates ; two other ridges or linese asperae traverse lon- 

 gitudinally the posterior concave side of the shaft ; one of them is broad and rugged, 

 the other is a mere linear rising. 



"The texture of the bone, which affords the chief evidence of its ornithic character, 

 presents an extremely dense exterior crust, varying from one to two lines in thickness ; 

 then there occurs a lamello-cellular structure of from two to three lines in thickness. 

 The lamellEE rise vertically to the internal surface of the dense wall, are directed ob- 

 liquely to the axis of the bone, decussate and intercept spaces which are generally of 

 a rhomboidal form, and from two to three lines in diameter. This coarse cancellated 

 structure is continued through the whole longitudinal extent of the fragment, and ini- 



' Aeiioj, surprising, ufiiti, bird. °- The ' Osteographie ' of Prof. De BlainvUle. 



VOL. III. — PART III. 2 I 



