Mr. H. Mace on BiiUerflies on the Nile. 241 



first section, the total number thus recorded on the Wliite 

 Nile being 75. This arrangement does not show at a 

 glance the total number of species found in each section, 

 and I have therefore made a fresh analysis of Dr. Long- 

 staff's figures, which I tabulate below. 



This arrangement shows clearly that the number of 

 butterflies on the White Nile diminishes steadily as the 

 river runs north, the species found in the highest latitude 

 being less than half those of the sub-equatorial district. 

 This is what one would naturally expect, for the upper 

 portion of the river flows through swampy and more 

 varied country, capable of supporting numerous plants, 

 without which insect life cannot be abundant, while the 

 lower portion is all dry desert, with little vegetation other 

 than that immediately bordering the stream. 



Mr. AVliitfeild's collection comprises a total of 27 species, 

 which I have hsted below. 



Nymphalidae. 



Dan mis chrysippus. 



var. 

 alcippus. 

 Pyrameis cardui. 

 Precis cebrene. 

 Hypolimnas misippus. 



Lycaenidae. 



Lampides baeticus. 

 Tarucus theophrastus. 

 CatacJirysops eleusis. 

 Zizera lysimon. 



Papilionidae. 



Herpaenia eriphia f. lacfei- 



pennis. 

 Belenois severina. 



,, mesentina. 

 Teracolus Calais. 



TRANS. ENT. SOC. LOND. 1922. 



Papilionidae (continued). 



Teracolus piJiisadia. 

 ,, protomedia. 

 ,, halimede f. acaste. 

 „ eupompe f. pseuda- 

 caste. 



,, evippe. 

 „ ephyia. 

 ,, evarne. 

 Catopsilia florella. 

 Terias senegalensis. 



„ brigitta (wet and dry 

 season forms). 

 Colias hyale var. marnoana. 

 Papilio demodocus. 



Hesperidae. 



Samngesa eliminata. 

 Gegenes nostradamus. 

 Rhopalocampta forest an. 



—PARTS T, II. (JULY) R 



