Shufeldt. — Oil the Affinities of Harpagornis. 665 



Art. LXIX. — On the Affinities of Harpagornis : a Letter to 

 Professor T. Jeffery Parker by B. W. Shufeldt, M.D., 

 Smithsonian Institution, Washington, dated 25th January, 

 1896. 



[Read before the Otago Institute, 8th October, 1895.'] 



It has given me great pleasure to do for your friend Mr. 

 Hamilton what you requested of me in your valued letter 

 of the 14th ultimo, just received. His excellent photographs 

 of the bones of Harpagornis, which came safe in your letter, 

 were studied by me with interest. I mounted all six of them 

 on cards, and yesterday compared most carefully all the 

 characters they presented with a number of American rap- 

 torial birds and others. I also compared what Haast had to 

 say on Harpagornis in the " Transactions of the New Zealand 

 Institute," vol. vi., 1873. 



Without any doubt whatever, Harpagornis has among 

 existing birds its closest allies among the true eagles, and the 

 relationship is by no means very remote. I compared it with 

 a skeleton of Aqidla chrysaetos, also with Thassa'etus pelagicus 

 and HalicBetus leucocephalus and others. In various parts of 

 its skeleton Harpagornis exhibits characters found in any one 

 of these several genera, and about in the same proportion : 

 that is, in a number of characters it agrees with Aquila, with 

 Thassa'etus in an equal number, and so on for Haliceetus and 

 others. It had a narrower skull in proportion to its length 

 than has any modern existing eagle known to me. The 

 pre-acetabular region of the pelvis of Harpagornis was also 

 very short, but this is a common character in many extinct 

 birds. Having fenestras in the sternum means but little among 

 eagles, as they may or may not be present in individuals of the 

 same genus. Moreover, I have seen sterna of eagles wherein 

 the fenestra occurred upon one side of the carina and not 

 upon the other. 



It is perfectly safe to say that Harpagornis represents 

 a more or less generalised aquiline type, and might easily 

 have been the common ancestor to a number of genera of 

 existing modern eagles, as, for example, Haliceetus, Aquila, 

 and Thassa'etus. In any natural scheme of classification it 

 might, with the greatest propiiety, be placed between the 

 genera Aquila and Thassa'etus, and it would be standing as 

 near where it belongs as we can possibly show at the present 

 time. 



