64 



Transactions. — Zoology. 



generally mucli larger than the male bird. Moreover, when comparing the male 

 and female skeletons of CircAis with each other, there are some slight sexual 

 differences easily discernible, which might suggest that they belonged to two 

 nearly allied species, did we not know their real relations to each other. 



As I shall show further on, the bones of both specimens Qi Harpagornis belong 

 to adult birds, of which the largest died at a more mature age than the smaller 

 one. Thus the smaller specimen might possibly be the male of H. tnoorei, 

 assuming the latter to be the female. However, as I am not able to settle 

 this point at present, I shall propose for the second and smaller specimen the 

 specific name of H. assiniilis, in order to point out the close relationship of 

 both. 



Dr. Hector suggested* to me that the Harjyagornis might possibly be the 

 Hokioi of the Maoris, which, however, according to Buller, is the Great Frigate 

 Bird (Fregata aquila), obtained repeatedly in I^ew Zealand, and of which he 

 gives several instances in his work on the birds of New Zealand.t 



"What the large bird of prey is that I have met several times during my 

 explorations amongst the snow-clad ranges constituting the Southern Alps, 

 without being able to secure a specimen, is a question which I hope future and 

 more fortunate explorers of those regions will one day solve. 



Before offering a description of the extremities of Harpagornis, I wish to 

 draw attention to the following table of measurements, in which I have placed 

 in juxtaposition the length of the principal leg and wing bones of all the 

 diurnal birds of prey of which I had material for comparison. 

 Table of Measurements. 





Harpafjornis 

 moorei. 



Harpagornis 

 assimilis. 



Aquila 



audax, 



Australia. 



Circus 

 assimilis, 



New 

 Zealand. 



Hieracidea 



novm 

 zealandice. 



New 

 Zealand. 





Inches. 



Inches. 



Inches . 



Inches. 



Inches. 



Metatarsus - - 



6-08 



5-87 



4-63 



3-47 



2-25 



Tibia - - - 



9-52 



S-92 



7-04 



4-26 



2-91 



Feraur - - - 



6-66 



22-26 



6-09 



20-88 



4-90 

 16-57 



2-79 

 10^52 



2-22 

 7-38 



Humerus - - 



— 



8-57 



8-20 



4-06 



2-35 



Ulna - - - 



10-06 



9-35 



9-38 



4-81 



2-65 



Metacarpus - - 



— 



4-48 

 22-40 



4-45 

 22-03 



2-47 



1-61 

 6-61 



11-34 



In comparing, in the first instance, the length of the femur with the 



* On the authority of Sir George Grey. Trans. N.Z. Inst., Vol. V., p. 435. — Ed. 

 t BuUer's "Birds of New Zealand." 4to., 1873. P. 340.— Ed. 



