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VIII. Butterjlies on the Nile. By Herbert Mace. Com- 

 municated by Dr. G. A. K. Marshall, F.E.S. 



[Read March 1st, 1922.] 



The river Nile, apart from the hmnan interest attached 

 to it, because of the plentiful remains of ancient civilisation 

 found on its banks, is particularly interesting to biologists, 

 because it forms the only practical Hnk between the 

 Ethiopian and Palaearctic regions. All the country, 

 including Lower Egypt, lying to the north of the great 

 desert, contains a fauna of Palaearctic character, and 

 there is such a small belt of fertile country bordering the 

 river as it flows through the desert land that only very 

 few forms of hfe belonging to the respective regions can 

 here intermingle. 



Some light is thrown on the manner in which the dis- 

 tribution of species has been brought about, by a study 

 of the butterflies which have been taken by various 

 collectors on the Nile during the last ten or twenty years, 

 and a collection which I have just received from Mr. 

 B. W. Whitfeild, a keen collector, who has been stationed 

 at Khartoum for a year, is of very special interest, chiefly 

 because, unhke those of other collectors, who have generally 

 passed up the river and stayed only a brief time at certain 

 points, the specimens have all been taken within a five- 

 mile radius of Khartoum itself; and although it may be 

 poor in comparison with what an even less thorough 

 entomologist might make in richer parts of the tropics, 

 the collection is much larger than any previously made 

 by a single collector at that place. 



All former records have been exhaustively summarised 

 by Dr. Longstaff in a paper pubHshed in the Entomological 

 Society's Transactions, June 13, 1913, and a comparison 

 of the insects received from Mr. Whitfeild with those 

 listed by Dr. Longstaff produces some extremely interesting 

 results. 



Dr. Longstaff divides the area with which he deals into 

 five parts. Under the first, Lats. 16-14° N., which includes 

 Khartoum, he enumerates 25 species, and under the other 

 sections, each of which includes two degrees of latitude 

 further south, he lists additional species to those in the 



TRANS. ENT. SOC. LOND. 1922. — PARTS I, II. (JULY) 



