396 MR. R. SWINHOE ON THE BIRDS OF CHINA. [May 2, 



Cuculus canorc'ides, S. Mull. 



Cuculus optatus, Gould. 



Cuculus canorits, Ibis, 1 863, p. 396. 



Cuculus monosyllabicus, Swinh. Ibis, 1865, p. 545. 



Cuculus helungensis, Swinh. Ibis, 1863, p. 394. 



I have a large series of this form of Cuckoo from Amoy, Formosa, 

 and Pekin, and find them so variable in size, and in length and form of 

 bill, tbat I give up in despair making species of them. From South 

 Formosa I got a specimen with small bill and peculiar note ; this I 

 described as C. monosyllabicus ; but it agrees with a specimen from 

 Java labelled C. tenuirostris, Temm., sent me by Prof. Schlegel ; 

 and a series from Amoy and a bird from Pekin are also the same. 

 From North Formosa I procured birds with large and long bills. 

 These I described as C. helungensis, and I have a specimen from 

 Amoy with the same features (noted as C. micropterus, P. Z. S. 1 863, 

 p. 265) ; but they do not possess a single other character to distin- 

 guish them. From Amoy I have one with a particularly short and 

 broad bill, but also with no other character ; and a second with a 

 thick curved bill, of large size, and with all the claws deep black. 

 This last I determined as C. canoroides of S. Midler ; but on glancing 

 through my series I find many of the lesser and small-billed form, 

 as also many of the long-billed form, with more or less black claws, 

 in fact almost every gradation from pure yellow to black. I come 

 therefore (I must confess, most reluctantly) to the conclusion that 

 they all belong to the same variable species. 



Like all the Cuckoos, these birds in China are only summer 

 visitants. 



461. Treron Formosa, Swinh. Ibis, 1863, p. 396, 1865, p. 540, 

 1866, p. 312. 



South Formosa. 



462. Sphenocercus sororitjs, Swinh. Ibis, 1866, pp. 311, 406. 



Sphenocercus formosa, S , Ibis, 1866, p. 122. 



Treron chceroboatis, Ibis, 1866, pp. 313, 406. 



South Formosa. Like Treron sieboldii, T. & S., of Japan, but 

 yellower about the head, and with the green of the back, wings, 

 and tail clearer and not washed with the brownish oil-colour of the 

 other. 



463. Osmotreron domvilii, Swinh. Ibis, 1870, p. 354. 

 Hainan. 



464. Carpophaga sylvatica (Tick.); Ibis, 1870, p. 355. 



Columba sylvatica, Tickell, J. A. S. ii. p. 581. 

 Hainan. 



465. Columba livia, Briss. Av. i. p. 82 j P. Z. S. 1870, p. 444. 

 In a feral state about the Pekin plains. 



