420 BULLETIN OF THE 



(except the Alcidce) are also sedentary throughout nearly their whole 

 range. In the Eastern Province, Larus, Stercorarius, and their allies, 

 as well as Columbus, are restricted in the breeding season to its north- 

 ern half, as are also, as already remarked, most of the water birds, 

 except the Rallidce and the Herodiones, which are chiefly southern. 

 The representatives of the Troglodytidce and Icteridce increase rapidly in 

 number towards the tropics, while the Mi mi ace and several genera of 

 the more brightly colored Fringillid<e are confined to the southern half 

 of the province. The Sylvicolidce, the most exclusively distinctive 

 family of the North American temperate region, reaches its maximum 

 development in the Middle and Cold-temperate Districts. The sec-, 

 tion Sylvicolece, and especially the genus Dendroeea, is more numer< 

 ously represented in the Eastern Province than in the Western, and 

 the greater part breed in the colder latitudes, their "metropolis" dur- 

 ing the breeding season being the Canadian Fauna of the Eastern 

 Province and the corresponding fauna of the Western. The species 

 of the section Vermivorece (genera Helmitherus and Helminthophagct) 

 have a wider longitudinal distribution than the Dendrcecce, the species 

 of which genus are mainly restricted either to t he Eastern or to the 

 Western Province. The two species of Helmitherus are southern in 

 their distribution, while four or five of the six Helminthophagce are 

 northern. 



V. At the extreme north, or from the Arctic coast southward to the 

 Canadian Fauna, nearly all the birds are migratory, owing to the 

 extreme severity of the winter season ; they also spend a smaller 

 portion of the year at their breeding stations than do the species 

 which breed farther to the southward. Even as far south as the Alle- 

 ghanian and Carolinian Faunae, the greater proportion of the species 

 are to a greater or less extent migratory. In die Carolinian and 

 Louisianian Faunse a much greater proportion are resident, even in- 

 cluding many species whose boreal limit of distribution is the Carolin- 

 ian Fauna. From the Hudsonian Fauna southward many species are 

 found the whole year at tin' same localities, and are hence termed 

 "resident," though the individuals representing such species are migra- 

 tory, there being a general movement of the winter habitat southward, 

 lint too limited to carry the wave of migration entirely beyond the 

 southern limit of the summer habitat of these species. 



VI. The representatives of the various groups differ from each other 



