BEAN-GEESE OF ASIA. 557 



I may add, that in A. sibiricus, Alpher. number of " teeth " on one side of the 

 upper mandible is 26, in all other specimens not more than 20. As to the 

 general colouring of these specimens — Ans. brachyrhynchus, Baill., is at a glance 

 distinguishable by its very pale general colouring, especially by lavender-grey 

 secondary coverts. Among others A. cameirostris, Buturl., is conspicuous by 

 its darker brownish head. All others are very much alike, showing only slight 

 individual variation in shade of colouring. The specimen named " oatesi " 

 indeed being quite identical in this respect with Swinhoe's specimen of 

 " serrirostris" (H. E. Dresser in litt.). 



A. oatesi was described twice : in Bull. Br. O. C. v. LXXVII, p. 46, by Mr. C 

 B. Rickett. and in v., XVII, No. 1 , p. 49 of this Journal by Mr. E. W. Oates, who 

 thought that it does not " require any further description." s In these de- 

 scriptions it was stated that the bird is " similar in size and plumage to A . bra- 

 chyrhynchus, but with a much larger bill " and Mr. Oates suggested that it is 

 always separable from A. segetum by length of wing. 



Now we see, that in size — length of wing excepted f — as in colouring this 

 bird has nothing at all to do with A . brachyrhynchus, and, on the other hand, that 

 such length of wing as 17-5 inch. (445mm.), or even 16-4 inch. (416 mm.) is of 

 no use as distinguishing character, small though adult specimens of A. car- 

 neiro*tris, A. segetum, A. serrirostris having such wings. The bill of the bird, 

 as Mr. Oates himself states, is very much like that of A. segetum, but longer 

 and higher. In other words it is the bill of A. serrirostris, and in fact the bird 

 is identical with Swinhoe's specimen. 



It can be readily understood how this error, especially the strange comparison 

 with A. brachyrhynchus, originated. A. segetum is exceedingly rare without the 

 limits of Russia, and even here not common. Messrs. Oates and Rickett had 

 evidently never seen this bird (Mr. Oates states this to be the case, p. 39, No. I, 

 v. XVII of this Journal) ard imagined it to be of the same size as the common 

 English A. arvensis, Brhm. (as Mr. Oates himself says, I.e. p. 43). Therefore 

 having in hand a Chinese Bean-Goose of much smaller size than A. arvensis 

 they stated it to be " like A. brachyrhynchus " disregarding peculiar colouring 

 of this last. 



Now I must state my reasons for identifying my Kolyma birds (and " A. 

 oatesi ") with A. serrirostris of Swinhoe. First of all, not only colouring of 

 feathers, but all dimensions and size and shape of bill are the same in all these 

 birds (length of nail more than \ of the length of exposed culmen ; number of 

 '• teeth " on each side of upper mandible about 20 ; depth of bill more than 

 1, 3 inch ; depth of lower mandible 0-35 — 0"47 inch). Further, Bean-Geese 

 with characters just pointed out swarm not only on Kolyma, but in other parts 



* Though size of the nail and depth of lower mandible were not stated (they are recorded 

 for the first time in the present paper), and without these characters Bean-Geese are im- 

 possible to identify, as Mr. Oates must know as well, as anyone, for he was the first to 

 point out the usefulness of one of these characters, some nine years ago. 



t Length of wing, as is easy to see, is quite a useless character in these birds. 



5 



