332 GEOGRAPHICAL DISTRIBUTION 
to 3 if not 4 genera of Pusseres, are found nowhere else in the New 
World,! and their occurrence there does not preclude us from set- 
ting them down as essentially Palearctic forms. Indeed they all 
belong to genera widely distributed throughout the greater part 
of Europe and Asia, while if the species be not identical they are 
represented by others that are closely cognate—as in the case of 
the WAGTAILS? and the BULLFINCH. Some are summer immigrants, 
and therefore must yearly cross and recross Bering’s Sea, since they 
assuredly do not winter upon the American side. To these last 
may even be added the WHEATEAR, Sazicola cwnanthe, for though 
that species is. known as a regular annual visitant to Greenland? 
and Labrador (where it breeds), and almost annually appears as a 
straggler in the maritime provinces of Canada, in Maine, and in 
New England, the flocks which throng the stony hill-tops of Alaska 
in spring are not likely to have performed a north-west passage 
from Europe, and indeed it is stated that specimens from Norton 
Sound differ considerably from those obtained in Greenland. All 
these birds are unseen in British Columbia,‘ and as all are migratory, 
the inference that they make some part of Asia their winter quarters 
is almost irresistible ;° but the point to be observed is that an orni- 
thologist passing in summer from Kamchatka or the eastern extremity 
of Siberia would on landing in Northern Alaska find himself in the 
midst of an Avifauna of which nearly one-half, namely 112 out of 
227 species, was identical with that which he had left on the other 
side of the Pacific.® : 
1 These are Pyrrhula cassini, Leucosticte griseinucha, Anthus cervinus, 
Budytes leucostriatus, Motacilla ocularis, Parus obtectus, Phylloscopus borealis, 
Cyanecula suecica, Surnia funerea, Strix lapponica, and Archibuteo lagopus. 
The purely American species which occur accidentally in Europe are of course 
left out of consideration. It is to be remarked that at present there is no trace 
of the accidental occurrence of any purely American species in Northern Asia, 
though such are quite likely to come under the notice of future observers. 
2 “Several small birds of the water-wagtail genus” came on board one of 
Cook’s ships, 16 August 1778, when in lat. 69.57 N. and long. 166.19 W., being 
then off Cape Lisburn on the northern coast of Alaska (W. Ellis, Narrative of a 
Voyage &c. i. p. 340). 
3 Though Messrs. Nelson and Henshaw (op. cit. p. 222) state that the present 
writer ‘‘ assumes that the bird reaches North-west America by the way of Green- 
land,” he does not remember having entertained or expressed any such opinion. 
On the contrary, he used the very words above printed in his article “ Birds” 
published in the Encyclopedia Britannica (ed. 9, iii. p. 753) in 1875. 
4 They seem not to occur to the southward of Cape St. Elias, the presumed 
limit of the Province. 
> This remark must be taken as not influencing the argument, or the example 
of Egypt presently to be cited would thereby be affected. 
§ It may be observed that in order to avoid the least appearance of overstating 
the case, forms like the TREE-CREEPER and Osprey have been counted as though 
distinct. If these and some others were regarded as specifically identical, and 
