Distribution of Birds in North JRussia. 181 



1st. "The S.W. District of the Southern Division." — 

 Included between 30° and 40° E. long, (and between 60° and 

 64° 30' N. lat.). This includes, in the west, Viborg in Fin- 

 land and the lake-districts of Onega and Ladoga, and, for con- 

 venience, the whole of the Olonetz Government with a portion 

 of the Archangel Government. 



2nd. " The S.C. 2)/6-«nc?!o/'^7ie Southern Division." — In- 

 cluded between 40° and 50° E. long, (and between 64° 30' N. 

 lat. in the north, and the southern boundary of the Vologda 

 Government, about 59° N. lat., in the south). This includes 

 the main portion of the water-system of the Dvina south of 

 Cholmogory and the upper valley of the Mezen. 



3rd. " The 8.E. District of the Southern Division." — In- 

 cluded between 50° E. long, and the eastern boundary of the 

 Perm Government, 60°-65° E. long, (and between 58° and 

 64° 30' N. lat.). This includes the remaining portion of the 

 Vologda Government eastward to the Ural, a part of the 

 Archangel Government, and part of Perm — in other words, 

 may be held as including the head-waters of the Petchora 

 and Dvina rivers, and the sources of the Kama flowing south- 

 wards. 



As with the Northern Division, I have tabulated the 

 records of the authors who have treated of the birds of the 

 Southern Division ; and I give below a list of these with 

 the titles of their papers*, indicating the extent of the authors' 

 field-work, or the districts in connexion with which they have 

 written, by capital letters (S.W., S.C, or S.E.) affixed to 

 the notice of each. 



In addition, in a second Table, I propose to institute a com- 

 parison between the faunas of the two Divisions as far as 

 recorded, thus showing a general outline of latitudinal as well 

 as longitudinal distribution. 



The cross-references by numbers -between the following 

 list and the Table, and vice versa, are continuous from the 

 former ' List of Authorities ' for the Northern Division ; 

 but authorities who have treated of the birds of both Divi- 

 sions retain the original numbers as given in the former list. 

 Thus the newly added authorities for the Southern Division 

 are numbered from 19 onward. 



* I entered the records in the Tables rather in the order in wTiich I 

 was able to consult the authors than in strict chronological order ; but this 

 is perhaps of minor importance. 



