16 Dr. G. B. Longstaff on 
the Bahr al-Zarafa throughout its length; also the Bahr 
al-Gebel up to Gondokoro and Rejaf. 
Gondokoro [Lat. 4° 54’ N., Long. 31° 41’ E.], situated 
on the right or eastern bank of the Bahr al-Gebel, is the 
most northerly station in Uganda. Rejaf, about eight 
miles south of Gondokoro, but on the left bank, is in that 
part of the Anglo-Egyptian Sidan which, under the name 
of the Ladé Enclave, was leased to the late King of the 
Belgians. 
The Bahr al-Gebel in the Sadd region, some forty miles 
south of Lake N6, reaches its most westerly point in Long. 
30° 8’ KE. From these data it will be seen that the region 
treated of is included within 23° of longitude, but extends 
over 11° of latitude—say a strip of 650 miles by 140 miles— 
though the distance by river is said to be 1,128 miles. 
Probably most of the butterflies sent to Europe have been 
taken within a very few miles of the river banks. 
Since the place-names given are for the most part those 
of small native villages, or of “ wooding”’ stations, there 
is no reason to expect that they will be permanent in a 
country where even Government posts are from time to 
time moved for administrative convenience, or more often 
from the proved unhealthiness of their sites; since, more- 
over, whether permanent or not, many of these names are 
not to be found even in the best atlases, it has been thought 
well to give the approximate latitude of each locality. 
Of course the latitude is not of much service in the case of 
places situated on the part of the river running nearly due 
east from Lake N6 to Kéd6k (Fashdda). 
Entomologically this district is but little known, so, 
having visited it myself twice, in February 1909 and 
again in February 1912, it seemed worth while to gather 
together the stray notes of travellers and sportsmen, to 
form the basis of a local list. I have been confirmed 
in this resolve by the discovery that my captures would 
appear to exceed alike in numbers of species and specimens 
those of my predecessors. But it must not be forgotten 
that the district has not been systematically worked, and 
especially must it be kept in mind that little is known of 
the wet-season fauna. 
