44 THE ZOOLOGIST. 



from Mr. Alpheraky on the subject, which I think will prove very 

 interesting : — " In the younger A. arvensis (let us say up to four 

 or five years) the black and orange of the bill is disposed very 

 much in the same way as these two colours are disposed in 

 segetum. And this is the reason why the great confusion has 

 arisen. The colouring being similar, people could not dis- 

 tinguish the two species. In such cases the form of the bill and 

 the proportions of the nail to culmen will always (I think) help 

 to settle the question, and often the number of teeth will also 

 serve as a sure guide in difficult cases." 



I have lately had the opportunity of making a careful exami- 

 nation of four freshly killed specimens of segetum, shot in Holland 

 by Mr. J. M. Pike, who at once forwarded them to the British 

 Museum. He says : — " We obtained five specimens out of a 

 small family of six Bean-Geese. These turned out to be all well- 

 marked examples of A. segetum in two old birds and three young 

 ones." The following gives the length of bill along culmen, 

 including the nail, and number of laminae of these four speci- 

 mens, which are true segetum, having the large elliptical nail so 

 characteristic of the species, which in arvensis is proportionately 

 much smaller and rounder : — 



1. Ad. $ . Laminse each side, 21. Bill, 2§ in. 



2. $ . Laminse each side, 24. Bill, 2 T 5 6 in. 



3. ? . „ „ 21. „ 21 in. 



4. ? . „ 22 left side, 21 right. Bill, \\% in. 



Although considerable variation exists in these four birds' bills, 

 they are quite distinct from arvensis, both in form, colouration, 

 size of nail, length of bill, and number of laminse. Mr. Alpheraky 

 agrees with me in saying the number of laminse in segetum varies, 

 attaining to as many as 24 in some specimens, just as occurs in 

 A. brachyrhynchus, and states that he has a specimen of segetum 

 from Kulguev with 24 ; but in the great majority of specimens 

 of both segetum and brachyrhynchus the number is from 20 to 21. 



The chief points of difference between segetum and arvensis 

 will be readily seen by reference to the accompanying plate and 

 following descriptions : — 



Fig. 1, Anser segetum, $ . — Bill (upper view) : average length 

 of culmen about 2j in. ; nail large and elliptical — the nail has a 

 different length in proportion to the total length of the bill in the 



