49 
The Binds of Cookham and the Wcighbourbood, 
Continued from page 80, Vol, IT. 
—e 
Fam. Sytvicormz. Sub-fam. Moracm1ine. 
b. Calobates. 
40. Motacilla sulphurea. § Tho Grey Wagtail. 
Although generically separated by recent authors under the 
name Calobates, I cannot find any real difference of structure 
. - between this form and true Dotacilla, and I can only suppose the 
| genus to have been founded on a difference in the style of plumage. 
This sort of genus-is greatly in vogue now-a-days, especially 
among the German and American systematists, and, although I 
allow that there are many very distinct genera un-recognised by 
such well-known ornithologists as Yarrell, Morris, &e., I cannot 
but admit that such multiplications of genera as the extensive 
systematists allow, are unesseutial to the advancement of science, 
-and tend greatly to perplex the student. 
Such are the considerations that induce me to dissent from the 
recognition of Calobaies by Mr. Gould, in the lately published 
part of the ‘Birds of Great Britain.’ I perceive only a slight 
difference in the beaks of Motacilla Yarrelli and WU. sulphurea, 
T hat of the latter is a little thinner and more elongated, but as 
the relations of the primaries to each other in both species are 
the same, and the habits of each bird so similar, I cannot allow 
the more slender beak and legs of IZ we to be more than 
a specific character. 
_ The Grey Wagtail is rarely observed in its summer dress in 
this country, though I believe it breeds in the north of England. 
At all events, I saw eggs said to be of this species in more than 
_ one collection near Peterborough. Mr. Harting says in his 
‘Birds of Middlesex’ (p. 64):—‘‘ Although I have found the 
_ Grey Wagtail breeding in Northumberland in May, yet in the 
_ south it appears to bo only a winter visitant.” I subjoin a very 
_ interesting note by Mr, Gould, and as it relates to the breeding 
{ G 
