102 
pierin^:. 
The flight of C. pomona as regards the $ is, if possible, more rapid and erratic than that 
of C. pyranthe , but from its bright colouring the $ is conspicuous on the wing. I have sometimes 
seen Bulbuls and various Flycatchers attempt to seize this butterfly in flight, but apparently they 
never succeeded, and soon abandoned the chase. 
Dercas verhuelli, Van der Ho even 
This handsome butterfly, though local and keeping to wooded districts, is fairly common 
where it occurs, but I have only taken it from February to July inclusive, March, April and May 
being the months when it is most numerous ; like Catopsilia pomona it appears intermittently 
even during these months ; for a few days to be seen in numbers, then almost absent for some weeks. 
At the proper season it is usually common in the “ Happy Valley” at Hongkong, and always seems to 
be plentiful at Pak-shan, a wooded part of Lappa or Patera island, (Tai-lien-shan in Chinese) on 
the opposite side of the harbour to Macao. The foodplant of the larva grows there in profusion, 
and is in full bloom in March, the small but clustered white flowers forming large white patches 
everywhere against the varied greens of the wood, most of which occupies the slopes and summit 
of a hill in which are numerous horse-shoe graves, to whose presence the wood probably owes its 
partial immunity from the firewood-gatherers. 
Dercas has a fairly swift but haphazard flight, often much like a piece of paper floating 
erratically to the ground—first one way then the other, jerkily—so that it does not cover the ground 
at a fast rate, but it is fond of threading through trees and jungle, often rather high up, and has a 
knack of disappearing very suddenly amongst bushes, where it settles with close wings on the un¬ 
derside of leaves. Its square-cut outline and the colouring remind one somewhat of the “ Brimstone ” 
butterfly so common at home, but its flight and habits are quite different, as above indicated. 
When freshly emerged from the pupa it is a lovely insect, but unfortunately it is not a butterfly 
which displays its beauty much, even in the places it frequents, and besides being local is limited 
to a rather brief period on the wing in this part of the world. Often it takes but spasmodic flights, 
settling suddenly on the underside of leaves, whence it again flies jerkily to another leaf, and so on 
several times in succession, till it finds a hiding-place which pleases it, where it will remain a con¬ 
siderable time. Dercas seems rather fond of the flowers of Dalbergia benthami and is occasion¬ 
ally to be seen at Lantana and a species of Musscenda , but it does not appear to care much for any 
other flowers. 
D. verhuelli seems to occur in two forms, as in the case of Papilio clytia: both 
varieties being almost equally common. One form has a large apical dark brown patch in the 
forewing (Fig. i, PI. XIII) : the other form has no apical patch, and but a very narrow dark 
edging of the forewing ; but in both forms the females always appear to have the apex of the 
forewing much more produced and hooked than in the males, and the females are of a very pale 
chrome on the upperside, whilst the males are a brilliant yellow. Both forms occur together at the 
same season, and the form lacking the apical patch in the forewing (Fig. 2, PI. XIII) was named 
D. skertchlyi by de Niceville, but although I have not bred a long series from one $ and have 
not obtained the two forms from the eggs of one ?, no difference is discernable in egg, larva or 
pupa of either form, which both feed on the same plant. 
