1893.] NATURAL (SCIENCES OF PHILADELPHIA. 27 



sentative of Califomian and Sonoran sub-regions, such as Glauci- 

 dium gnoma ealifornicum, Syrnium oecidentale, Coccyzus americanus 

 oceidentalis, Vireo huttoni (pbscurus), Salpinctes obsoletus, and Psal- 

 triparus minimus. There is also a slight intermingling element of 

 typical eastern forms in the central and northerly part of the Pacific 

 coast fauna due to similarity of its climate to that of the North 

 Atlantic coast and the accessibility of the region to migrants from 

 the northwest interior and Alaska. Thus we have Spizetta soeialis, 

 Empidonax pusillus traillii, Dendroica coronata, Spinus tristis, Colap- 

 tes auratus (?) and Sylvania pusilla breeding on Vancouver Island, 

 while in the interior of British Columbia, east of the Cascades, these 

 are wholly, or for the most part, replaced by Spizella soeialis arizonce, 

 Empidonax pusillus, Dendroica auduboni and Colaptes cafer, Spinus 

 tristis appearing (?) to be absent. 



As a whole, the province of British Columbia includes a diversity 

 of faunal characters which no single geographic area in America 

 can match. As a result it may further boast of a longer list of 

 summer residents than any equal area included in the A. O. U. 

 check list limits. Approximately these number 330 in British Col- 

 umbia. In the rest of British America, an area ten times larger 

 it is about 365; in the Middle States, 177, and in the United 

 States east of the Mississippi, 300. This exceptional showing is 

 brought about by a conjunction, intrusion and overlapping of the 

 Arctic, Boreal and Transition life zones. It is further complicated 

 by the westerly extension of Atlantic-boreal forms to the Pacific, 

 the intrusion of upper Sonoran species into the central, arid region, 

 the straggling of Pacific coast forms across the Cascades, the sojourn 

 of Arctic species on the higher mountains and " barren grounds" 

 of the north and the southward migration of all, including land and 

 marine species of the polar regions, across common territory. This 

 cosmopolitan feature of British Columbian biology makes the study 

 of its zoogeography both difficult and fascinating. Mr. Chapman 

 has pointed out some of these peculiarities in his paper on the 

 Streator collection, and considering that he had no personal acquain- 

 tance with the country, his deductions are remarkably just. After 

 what has been said on the subject, however, we cannot admit that 

 in British Columbia " faunal lines are not so complicated " as in 

 "northern California," for they are infinitely more so. Mr. Chapman 

 has drawn close lines for the eastern boundary of the habitat of 

 so-called " coast forms," but of the thirty-one species enumerated 



