39C Mr. R. Swinhoe on Formosan Ornithology. 
yellow. Iris light chestnut-orange. Legs and claws orange; 
the toes lighter, and some of them washed over the greater part 
with blackish grey. Ear-covert roundish, smaller than the eye, 
the aperture occupying the upper semicircle. 
The colours of the Cuckoos are too variable to hope upon them 
to establish specific characters. The form and size of the bill 
appear to be the most constant characters, and these require 
personal comparison to ensure correct identification. 
I have frequently met with the North-Formosan Cuckoo in 
my rambles, but have unfortunately never heard its notes. It is 
a common summer bird about all the hilly region near Tamsuy 
and Kelung. 
107. Cuculus CANORUS, L. 
On the coast near Taiwanfoo I procured a stray specimen of 
this species. Mr. Blyth has examined and identified it. It was 
procured in September, and was apparently on its southerly mi¬ 
gration. I never heard or saw the European Cuckoo at any 
other time in Formosa. 
108. Treron Formosa, sp. nov. 
I have unfortunately only a female of this interesting Green 
Pigeon. It was shot in the neighbourhood of Taiwanfoo on the 
21st August 1861, where it was a rare bird. I had an oppor¬ 
tunity of once seeing a male close to my garden in that city, and 
I was told by a mandarin that he had kept a pair alive in a 
cage. It is a forest-loving bird, and, I dare say, not rare in the 
mountains of the south; but in the mountain-forests inland of 
Tamsuy I did not meet with it. 
Length 12f in.; wing 7^; tail 4, somewhat wedge-shaped, 
the feathers being rounded at their tips. Bill, basal two-thirds 
cobalt blue; apical pale, with a tinge of yellowish. Bare skin round 
the eye bluish grey. Iris comprising a bluish grey ring round 
pupil, then a narrow black ring, then a pearl-grey ring, and 
lastly a broad black ring. Legs madder-pink, with pale yellowish 
soles and blackish brown claws. Upper parts rather dark green, 
yellow on the head and rump. Throat grey, each feather mar¬ 
gined with yellowish green. Breast and belly yellowish green, 
yellower on the belly. Abdomen primrose-yellow. Flanks and 
