64 Transactions.— 2001097. 
generally much larger than the male bird. Moreover, when comparing the male 
and female skeletons of Cireus 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 of 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. moorei, 
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. assimilis, in order to point out the close relationship of 
both. 
Dr. Hector suggested* to me that the Harpagornis might possibly be the 
Hokioi of the Maoris, which, however, according to Buller, is the Great Frigate 
Bird (Fregata aquila), obtained repeatedly in New 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. 
i Hieracidea 
Aquila Circus nova 
Harpagornis| Harpagornis audax assimilis, zealandiae 
moorei. assimilis. 57 аб i ан - AREA: 
Hn Zealand. 
| Inches. Inches. Inches. Inches. Inches. 
Metatarsus - - 6:08 4:63 3:47 225 
Tibia жле ж 9-52 8:92 7:04 4:26 2:91 
6:66 6:09 4'€ 2:79 2-99 
Е. е, E. Hsec nist Wisi ned ar kel emen 
TES | $236 20:88 16:57 10-52 7:38 
Humerus - - Mu 8:57 8:20 4:06 2:35 
Ulna ае 10°06 9:35 9:38 4'81 2:65 
Meier. 2. | ДЕ 49 | 6 | щш 
22-40 S at 11:34 6:61 
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. —Ep. 
+ Buller's * Birds of New Zealand." 4to., 1873. P. 340. — Ep. 
