36 MR. A. R. WALLACE ON THE PAPILIONIDÆ 
The numerous specimens of Ornithoptera which I obtained in various parts of New 
Guinea and the adjacent islands show so much instability of form, colouring, and even of 
neuration, no two individuals being exactly alike, that I am obliged to include them all 
in one variable species, to which I believe must also be referred O. Pronomus, G: R. 
Gray, from Cape York, O. Euphorion, G. R. Gray, from North Australia, O. Archideus, 
G. R. Gray (ex Boisd.), erroneously said to be from Celebes, and O. Boisduvalii, Mon: 
trouzier, from Woodlark Island. 
Var. a, Aru Islands (Wall.). O. Arruana, Feld. Lep. Frag. p. 24. 
Individuals from this locality differ in the arrangement of the nervures; in some the 
third subcostal nervure of the upper wings branches from the same point with the upper 
disco-cellular, in others considerably beyond it; the points from which the subcostal ner: 
vures branch also vary. The amount of green colour on the median nervure and its 
branches varies. In some specimens there is a spot at the anal angle of lower wings be- 
neath, agreeing with O. Pronomus, G. R. Gray ; but this is generally wanting. 
Var. b, Dorey, Salwatty, south-west coast of New Guinea (Wall.). 
These agree very closely with O. Poseidon, as figured by Westwood; they differ indivi- - 
dually in the same manner as the last, and also in the length of the lower disco-cellular ner- 
vure on the under wings. They have generally no golden spots beneath the wings. They 
vary also in the outline of the under wings, the outer and anal angles being more acute 
in some specimens than in others. Some have the under wings of a uniform green en- 
tirely without spots, while others have a range of black spots more or less fully developed. 
Var. e, Waigiou (JFall.). Archideus, G. R. Gray, 9. 
This agrees with the last; but the male is of a more delicate green than any of the 
others, and has less of that colour on the median veins. On the under side there are n0 
golden spots. The whole surface has a golden tinge, and the central portion of the lower 
wings is tinged with amber-brown. | 
The females of all the above vary extremely, much more even than the males, and from | 
the same locality two specimens are rarely alike. The discoidal cell is in some specimens | 
more than half occupied by a whitish patch, while in others there are only a few small | 
spots. One of my specimens from Salwatty almost exactly agrees with that figured by 
Westwood (Cat. of Or. Ent. pl. 14) as from Cape York. One of the Waigiou specimens i$ | 
the same as Archideus, G. R. G., figured by Boisduval (Voy. de l'Astrolabe, t. 4. f. 1, 9. 
and another, from New Guinea, differs very little from Euphorion, G. R. G. (Brit. Mus 
Cat. Lep. pt. 1. pl. 2. f. 3), from North Australia. | 
From these facts 
an extensive area, 
I am led to conclude that we have here a variable form spread Over 1 
rea, and kept variable by the continual intercrossing of individuals, which. 
would otherwise segregate into distinct and sharply defined races. The same area 5 . 
inhabited by many species of birds common to all parts of it; and just as the birds d 
Ceram and Amboyna are almost all distinct species from those of N | 
find those islands inhabited by the Ornithoptera 
species, readily distinguishable in either 
ew Guinea, so do W 
Priamus, a well-marked and constant 
sex from the inconstant forms of New Guines 
