418 
Mr. Cecil W. Barker's 
laris, and with the additional force^ that being a common 
butterfly I have had greater opportunities of watching 
it throughout the year. Transitional forms from T. 
regularis to T. desjardinsii are also common. 
Pieris saha has its recognized variety {Flavidaj Grandi- 
dier), which, to the best of my knowledge, is also 
seasonal ; it being a rare winter form. The of this 
variety, which is not described in South African 
Butterflies/' Trimen, is on the upperside similar to the 
summer form, except in its smaller size, acuter apices 
of forewings, and absence of the black nervular spots of 
the hindmargins of the hindwings. The underside is 
tinted, of a similar colour to that of P. saha, 6 . I have 
three recorded captures of the ^ Flavida as follows 
—May 25th, 1890, July 27th, 1890, and Aug. 25th, 
1890, also one ?, May 8th, 1890. 
Pieris pigea is a purely summer or wet season form, 
being replaced by P. alba in the winter or dry season. 
Transitional forms occur between the seasons, which 
exhibit a gradual approximation to P. alba, by the at- 
tenuation of the nervular black spots of the hindmargins 
of the upperwings and in the ? , also of the discal spot 
of the forewings. P. alba, $ , on the upperside is devoid 
of all the nervular black spots of hindmargins of wings, 
common to P. pigea, and on the underside has the apices 
of the forewings and the whole of the hindwings tinted. 
P. alba, ? , has two distinct forms ; one which exhibits 
the same tint of underside as the and the other 
exhibits a rich orange-ochreous underside to hindwings 
and apices of forewings. Everything points to the pro- 
bability of P. alba being the dry season form of P. 
pigea. 
For similar reasons I believe P. charina to be the 
winter, or, at least, seasonal form of P. simana, though I 
have, unfortunately, kept no notes of dates of capture of 
this butterfly to refresh my memory. However, I have 
certainly caught P. charina in the driest months of the 
year, and my captures of the typical P. simana, I am 
equally certain, have all been during the summer months, 
say from December to February. Intermediate forms, 
if such they be, with more or less slight irroration of the 
underside, I have met with both during these months, 
and more frequently during the autumn. These approxi- 
mate dates, I am aware, do not agree with some referring 
