GEOGRAPHICAL DISTRIBUTION 331 
Reaching the eastern frontier of Canada, it rapidly inclines west- 
ward and loses itself in the Arctic wilds. But this Province melts 
away also on its north-eastern border, and cannot there be sharply 
distinguished from what may be named the “Canadian,” which 
occupies the north-eastern portion of the continent, including the 
eastern half of the Dominion, and it must be held to extend across 
Davis Strait to Greenland, though it only fringes the shore of that 
ice-bound country, while here and there on the continent it follows 
the higher ranges southward, even to Fort Burgwyn near lat. 
37° N. if not further. Then on the west we have a “ Californian” 
Province, the longitudinal extent of which is very indefinite. 
Prof. Heilprin would cut off the southern portion, annexing it to 
the Neotropical Region, and its eastern boundary would seem to 
proceed along the Sierra Nevada and the Cascade Mountains, so 
that it is restricted to a mere strip of coast territory, extending, 
however, beyond British Columbia. Between this Californian and 
the Alleghanian Province is interposed a considerable tract of 
country called by many American writers the ‘“ Middle Province,” 
a name so vague that it would seem allowable to distinguish it as 
the “Missourian” since its characteristic vertebrates culminate 
(so to speak) in the wide basin of that greatest of tributaries to 
the Mississippi. Occupying the extreme north-west of the con- 
tinent, a fifth Province, the ‘“ Alaskan,” must be recognized, and 
this from a zoogeographical point of view is the most important 
of all, since it is characterized by the presence of Mammals and 
Land-birds, which are not only specifically identical with those of 
Asia, but among them some individually have an Asiatic resort. 
The list of Birds observed in this Province, which may be taken as 
beginning about Cape St. Elias, and thence extending northward to 
the Icy Sea, seems (after such revision as can at present be made) 
to number 227,? of which 112, or very nearly one-half, are also 
Asiatic. Dividing the whole into Water-birds and Land-birds, we 
find that of the former (127) more than 66 and of the latter (100) 
exactly 27 per cent. are found on both sides of the Pacific. More- 
over no fewer than 11 of the 100 species of Land-birds, belonging 
1 Indication of its being the focus (if such a thing can now exist) of purely 
Nearctic types is not wanting, since here we find at least one generalized or 
undifferentiated genus, Colaptes (FLICKER), which both to the north and to the 
south separates itself into specific forms. 
2 The gross number given in 1887 by Messrs. Nelson and Henshaw in their 
Report upon Natural History Collections made in Alaska (pp. 19-226) is 255, but 28 
of these should be deducted as not being known to occur to the northward of Cape 
St. Elias or the Alaska Mountains, where apparently a very natural frontier exists. 
This Report contains a useful bibliography of Alaskan ornithology. In making 
the estimates given in the text above, all the subspecies or conspecies recognized 
by the authors have been treated as true species. Were it otherwise the results 
would still more favour the views here expressed. 
