Middendorff's Goose 105 



specimens, mainly because he generally confounded the species M. arvensis and M. segetum. 

 Another error is the statement that the Turkestan A. middendorffii was identical with those 

 East Siberian geese which Middendorff, Schrenck, and Radde regarded as Anas grandis 

 of Pallas. 



Attention may also be directed to the author's inaccurate measurements of the bills of 

 Turkestan birds, namely, from 1.9 to 2 in. ( = 48.2-51 mm.), that is to say, dimensions so 

 small that they are not met with even in the smallest of the adult examples of the European 

 representatives of M. arvensis. Finally, the most serious misstatement of Severtsov's is 

 that East Siberian geese {A. grandis, Midd. nee Pall.) winter in Turkestan. 



All this at first completely threw me out, and it would hardly even now have been 

 possible to clear up the muddle, were not Severtsov's collection of geese preserved in the 

 Zoological Museum of the Academy of Science at St. Petersburg. From a detailed 

 examination of this material all became clear, although not without some labour. 



Not a single example of M. segetum from Turkestan is to be found in this collection ; 

 while the dimensions of the bills do not tally with those given by Severtsov. Moreover, not 

 a single specimen from Turkestan is identical with those from East Siberia ; while only the 

 largest male from Chimkent, with a culmen-length of 72 mm. ( = 2.83 in.), exceeds in this 

 respect the largest specimens from the Novgorod Government, the Ilmen, or from Novaia 

 Zemlia only by some \ or 1 millimetre, a difference too insignificant (for such large birds) to 

 serve for the identification of even this single example with the birds from East Siberia. 1 

 The hypothesis that geese arrive thence to winter in Russian Turkestan proves therefore to 

 be founded on false data. Accordingly I had no other course than to add the Turkestan 

 A. middendorffii to the synonyms of M. arvensis, Brehm, and to give a new name to the 

 Siberian form, wrongly held by Middendorff, Schrenck, Radde, and others to be A. grandis 

 of Pallas. We are now indeed aware that Pallas's description of A. grandis, based on 

 Gmelin's statements, and not upon his own examination of the bird, does not agree 

 at all with the goose here described, but must be referred to Cygnopsis cygnoides, and 

 probably to a domesticated or half-domesticated representative of that bird. I have there- 

 fore proposed for the East Siberian form of the yellow-billed goose the name Melanonyx 

 arvensis sibirieus. 



It may be indeed that it would be better to regard this goose as an independent 

 species, and not as a variety or sub-species of the yellow-billed bird ; but as the differences 

 consist only of the greater size of the bill and the arrangement of the black and orange 

 colouring (the latter being reduced to a narrow ring, bordering both mandibles terminally), 

 the absence of white feathering along the base of the upper mandible, the somewhat darker 

 colouring of the back, and the slightly larger dimensions of the whole bird, I do not find 

 sufficient grounds for taking this course. Moreover, the fact that with the increase in the 

 length of the bill in typical yellow-billed geese (once the culmen approaches 70 mm. 

 [ -2.75 in.]) the yellow-orange colouring rapidly yields to the black, which occupies more than 

 the basal half of the bill, points to a specific relationship existing between these two geese. 



As to the sculpture of the bills and relation of the upper nail to the total length of 

 the culmen, shown in the following drawings, the two forms of this goose offer no essential 

 difference. 



1 Mr. Buturlin mentions yellow-bills in the Novgorod Government with bills of more than 70 mm. along the culmen, and himself 

 brought from Novaia Zemlia in 1902 a bill with culmen 71 J mm. ( = 2.81 in.). 



