6 Trans. Acad. Sci. of St. Louis. 



what one should watch, particularly in order to make a dis- 

 covery of value. 



Apparently extirpated species are also retained in the list, 

 because it is interesting to know what formerly occurred in the 

 state, and because the possibility still exists that at least a few 

 individuals remain or have returned from adjacent regions. 

 Introduced species are also admitted as naturalized members of 

 our avifauna. 



The total number of species and subspecies contained in the 

 catalog is 383, of which 162 are breeders. Species not actually 

 taken within the limits of the state are distinguished by being 

 put into brackets. Of this kind there are 30, which subtracted 

 from 383 leave as the present status (July 8, 1907) 353 actually 

 observed species and subspecies for our state. 



IV. FAUNAL AREAS. 



Our avifauna is mainly that of the eastern United States 

 generally and differs little from that of the adjoining states on 

 the east, north and south. The Eastern Province reaches from 

 the Atlantic ocean to the foothills of the Rocky Mountains, 

 where the Middle Province begins, but many of the western forms 

 of birds extend eastward into Kansas and still more so into 

 western Nebraska, thus swelHng the number of species and sub- 

 species in the latter state to 415. Illinois, too, has a larger list 

 of breeders as well as of winter visitants, because her fauna is 

 enriched by water birds visiting Lake Michigan and by its great 

 north and south extension, which enters the Alleghanian faunal 

 area of the Transition zone in the north and reaches with its 

 southern end slightly into the Austroriparian area. 



Missouri belongs almost entirely to the Carolinian faunal area 

 of the upper Austral life zone; only the low alluvial counties of 

 the southeast can be considered a spur of the Austroriparian 

 faunal area of the Lower Austral life zone. The circumstance 

 that all our rivers of the southern slope of the Ozarks have wide, 

 open and long valleys leading southward gives an opportunity 

 f 01 a northward advance of southern forms of plants and animals ; 

 and our broad, open prairie region of the west and north offers no 

 barrier to an eastward spreadmg of the western fauna and flora. 



In comparing the avifauna of Missouri with that of the At- 

 lantic States in the same latitude it should be remembered that, 

 although the mean temperature differs but little, the climate of 



