XII. STINK-CLUBS,FEMALE “MABACUJABUTTEBFLIES” 665 
placed sometimes in the former group (Herrich-Schaeffer, Kirby), some¬ 
times in the latter (Doubleday, Felder). Partly for this reason, partly on 
their own account, these peculiar structures are worthy of further notice. 
The stink-clubs, as already mentioned, are situated, one on each side, 
on the posterior margin of the penultimate abdominal segment, below the 
stink-gland, and at the apical angle of the ventral plate of the segment. 
From thence, when the stink-gland is exserted, they are directed backwards 
and outwards. They consist of a chitinous stalk about 1 mm. in length, 
with a terminal club. The thickening is very gradual, and in Heliconius 
apseudes and eucrate \_narcaea ] (PL J, Fig. 5 A, B) the club reaches barely 
twice the diameter of the stalk. The pear-shaped extremity is somewhat 
thicker in Eueides isabella (PI. J, Fig. 6 A, B), and still more so in Dione 
juno (PL J, Fig. 7 B): it is approximately spherical in Dione vanillae 
(Pl. J, Fig. 8 A), Heliconius bescTcei (Pl. J, Fig. 4 A), and Golaenis \J\leta- 
morpha ] dido (PL J, Fig. 2 B), the diameter of the club head being nearly 
O’o mm. in the last-named species. 
The stalk is usually of a lighter or darker brown : in Eueides isabella 
(of which I have only examined a freshly emerged female) it is quite pale, 
almost colourless, but in Dione juno it is black. The head is usually paler 
than the stalk, and of a yellowish or brownish tint: I found it darker than 
the stalk in Dione vanillae . 
The head of the stink-club is covered with scales, which exhibit different 
forms in the different species. Those of Heliconius , especially H. apseudes 
(Pl. J, Fig. 3 B), approach nearest to the usual appearance of butterfly 
scales. Here one finds a few entirely regular scales, whose lateral margins 
are straight from the very point of attachment, diverging from each other 
at a more or less acute angle, and finally ending in about five long sharp 
teeth on the apical margin—scales such as one finds not uncommonly on 
the wings of many Heterocera. The apical teeth, which are sometimes 
almost thorn-like, are of a stronger consistence than the flat basal part 
which often seems to be folded or crumpled. Among these are numerous 
less regular scales, which can, however, be traced to the same type form. 
The scales of Heliconius besckei (Pl. J, Fig. 4 B) and H eucrate {narcaea) 
(Pl. J, Fig. 5 C) are similar, but as a rule even less regular and more bent 
or distorted. 
In Eueides isabella (PL J, Fig. 6 C) these scales are of stronger build, 
and their lateral margins, before diverging, run a short distance parallel, 
and thus form a stalk which extends to about one-third or one-half of the 
entire length: the “ palm” 1 is smaller than in Heliconius and usually divided 
into three long pointed teeth. 
Far coarser is the shape of the scales on the stink-club of Dione 
vanillae (PL J, Fig. 8 B); the palm has here entirely disappeared, and 
1 Germ. “ Spreite” = any spread-out part, such as the palm of a hand, which 
the scale closely resembles.—E.A.E. 
