1 64 SOUTH-AFRICAX BUTTERFLIES. 



usually about midway between forking of third and fourth nervules 

 and extremity of cell, but sometimes much nearer the latter ; upper 

 disco-cellular nervule very short, slightly oblique, sometimes a little 



curved lower one long, arched, occasionally angulated ; discoidal 



cell short, less than half length of wing, moderately wide, truncate at 

 extremity. Hind-tiings rather bluntly sub-ovate ; costa moderately 

 arched ; anal angle rather pronounced ; convex inner-margins forming 

 a o-roove covering three-fourths of abdomen ; first subcostal nervule 

 arched, given otf some distance before extremity of cell ; upper disco- 

 cellular nervule of moderate length, straight, oblique, — lower one con- 

 siderably longer, angulated above its middle point ; internal nervure 

 rather long, ending at some distance beyond middle ; ^ (in the Eclusa 

 group) with an elongate-ovate patch or badge of small, closely-set, 

 elevated scales near base, just above subcostal nervure. Legs rather 

 short and stout, scaly ; femora with long and rather sparse hair be- 

 neath ; middle and hind tibiae finely and sparsely spinulose beneath, 

 their terminal spurs of moderate size ; tarsi finely spinulose generally, 

 their claws very deeply bifid, without paronychia. 



Abdomen rather short, compressed but not very slender. 



This very compact and well-defined genus (of which the well- 

 known " Clouded Yellows " of Europe are typical) consists of a limited 

 number — variously estimated at from twenty-six to forty- eight — of 

 species, very closely allied, and mainly characteristic firstly of the 

 Pala3arctic, and secondly of the Nearctic Eegions. Several species are 

 circumpolar in the Northern Hemisphei'e, and the majority is in tem- 

 perate regions limited to high alpine tracts. It seems most probable 

 that Colias is one of the groups which was of very wide and general 

 prevalence during the last glacial period, but has since in tropical 

 regions been compelled to retreat to the mountains. Though extend- 

 ing all through America, from the extreme north (Gi'innel Land) to 

 Cape Horn, it is confined to the Andes in the great tropical belt ; and 

 in the Oriental Region only appears on the Himalayan boundary, with 

 the exception of an isolated species on the Nilghiris in Southern India. 

 Tropical Western Africa has yielded no representative of the genus, 

 but South Africa has one exceedingly common and generally distri- 

 buted species (Ekdra, Linn.), a very close ally of the European Edusa. 

 The latter is abundant on the African shores of the Mediterranean, 

 and Elcctra is recorded by M, Oberthiir as having occurred in Shoa on 

 the Abyssinian plateau, while Mr, Godraan has noted the occurrence of 

 a Colias (referred by him to Edusa) among Mr. Johnston's captures on 

 Kilima-njaro. 



These butterflies ai'e orange, orange-yellow, sulphur-yellow, or 

 yellowish-white above, with a more or less developed blackish border, 

 a black terminal disco-cellular spot in the fore-wings, and a larger 

 orange one in the hind- wings ; beneath, they are of a paler yellow, 

 always more or less tinged with green ; their antennEe and legs and 



