38 SOUTH-AFRICAN BUTTERFLIES. 



length ; costa scarcely arched beyond basal curve ; apex always marked, 

 and sometimes prominent and acute ; hind-margin straight, or very 

 slightly concave about middle ; inner margin usually slightly concave 

 about middle ; subcostal nervure four-branched, — first nervule given 

 off some distance before extremity of discoidal cell, short, often joining 

 costal nervure near its extremity {Cahjpso group), — second long, ending 

 not far before apex, given off rather nearer to first than to extremity 

 of cell, — third subapical, short or very short, ending at apex or just 

 before it (in Bvassicce group exceedingly short or even [P. Daplidice 

 and P. irellica] wanting), — fourth ending at or a little below apex; 

 upper radial nervule united with subcostal nervure at some distance 

 beyond end of cell ; upper disco-cellular nervule very oblique, usually 

 considerably more than half as long as lower one, which is transverse 

 and slightly curved ; discoidal cell rather broad, truncate at extremity, 

 more than half length of wing. Hind-ioings broad, rounded, some- 

 times rather elongate anal-angularly ; costa moderately or slightly arched ; 

 hind-margin very convex, entire or slightly sinuated ; anal angle 

 rounded ; inner margins meeting, and forming a tolerably deep groove 

 almost to end of abdomen ; first subcostal nervule much arched, given 

 off a long Avay before end of cell ; disco-cellular nervule s both oblique, 

 the upper one much shorter (sometimes less than half as long), the 

 lower one slightly curved. Legs moderately long and thick ; femora 

 with fine hair beneath ; fore-tibiee much shorter than femora ; middle 

 and hind tibire about as long as femora, their terminal spurs moderately 

 developed ; tibiae and tarsi finely spinulose. 



Abdomen curved, compressed, moderately long and slender, rather 

 larger terminally, tufted with silky hair at base on back, and more 

 thinly so along middle line beneath ; anal valves in ^ sometimes with 

 a short terminal curved spine {Calypso group) ; in other species, a 

 tuft of long bristly hairs beneath, just at base of each a,nal valve. 



Larva. — Rather elongate, shortly pubescent, slightly attenuated at 

 extremities ; head small. 



Pupa. — Rather slender ; much attenuated posteriorly ; a more or 

 less elevated ridge along middle line of back, and another on each side 

 of first three segments of abdomen ; an acute projection in front of 

 head ; and a prominent tubercle at middle of dorso-thoracic ridge, and 

 on each lateral abdominal ridge on second segment. 



Boisduval's list of this genus numbered (1836) no fewer than 

 166 species; Doubleday's (1847), 175. Wallace, after separating 

 from it (1867) the extensive sections Thysa, Tachyris, and Prioneris, 

 gave the number of described species as 1 7 i ; and if (as I consider 

 preferable) Tachyris be not separated generically, the total will be 

 raised to 237. Mr. Butler's revision of the genus was first given 

 (1870) in Cistula Entomologica, vol. i. pp. 39-5 2, and, as amended 

 (1872) in Proc. Zool. Soe. Loncl., p. 27, he still further divided the 

 old genus Pieris into fifteen genera, containing altogether 341 species, 



