16 Dr. G. B. Longstaff on 



o"- 



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 Sudan which, under the name 

 of the Lado Enclave, was leased to the late King of the 

 Belgians. 



The Bahr al-Gebel in the Sadd region, some forty miles 

 south of Lake No, reaches its most westerly point in Long. 

 30° 8' E. From these data it will be seen that the region 

 treated of is included within 2-|° 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 No to Kodok (Fashoda). 



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. 



