214 Mr. B. Swinhoe on Formosan Ornithology. 
Mr. Gurney tells me that he is informed by Mr. Blyth that this 
latter species has, in the adult form, both sexes coloured alike. In 
the broad, flat, open country of the south-west, near Taiwanfoo, I 
observed another Harrier, which I took to be C. cyaneus, L.; 
but of the species I cannot be sure, as it might have been one of 
two cognate forms which are hard to distinguish from it at a 
distance, except by a most experienced eye. These are the Pale 
Harrier (Circus swainsonii, Smith) and the American Harrier ( C. 
hudsonius , L.). The former of these has lately been procured by 
Capt. Blakiston on the Yangtsze Biver ; and of the latter, speci¬ 
mens may be seen in the Leyden Museum, from the Philippines 
and Kamtschatka. 
I procured no specimens of Harriers in Formosa; but as Mr. 
Gurney was anxious to have the Circus spilonotus figured, I have 
supplied a male and female, from the neighbourhood of Amoy, 
for that purpose. With reference to this species Mr. Gurney 
writes, “ I have just compared three male specimens of C. 
spilonotus with three males of C. melanoleucus, and enclose you 
the measurements, by which you will see that C. spilonotus con¬ 
siderably exceeds C. melanoleucus in all its measurements; in 
addition to which, it has a much larger bill and stronger tarsi. 
In all these respects (as also in some degree in colouring) it 
approaches to an allied but still larger species, C. assimilis, 
Gould, of Australia. I do not think that C. spilonotus ever 
assumes the black plumage which characterizes the head, neck, 
back, and a portion of the wings of the adult male of C. melano¬ 
leucus. I have not been able to compare your female of C. spilo¬ 
notus with a female of C. melanoleucus , the only (supposed) 
female which I have of the latter being an individual of the sex 
of which I do not feel sure. 
Total length 
Wing from 
Tarsus. 
Middle toe 
(inches). 
carpus. 
and claw. 
Circus spilonotus <5 
(3 specimens) J 
|22-23f 
171-171 
3§ 
2! 
Circus melanoleucus 1 
6 (3 specimens) J 
i 18 
141-15 
n 
2.” 
I have unfortunately no measurements of C. spilonotus taken 
from birds in a fresh state. The only note I can find in my 
journals is the following, made on a male shot at Amoy, the 27th 
