36 MR. A. R. WALLACE OX THE PAPILIONID.E 



The niimcrous 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 

 ncuration, no two indi^-iduals being exactly alike, that I am obliged to include them all 

 in one variable sjiecies, to which I believe must also be referred 0. Pronomits, G. R. 

 Gray, from Cape York, O. Enphorion, G. R. Gray, from North Australia, 0. Archideus, 

 G. R. Gray (ex Boisd.), erroneously said to be from Celebes, and O. JBoischivalii, Mon- 

 trouzier, from "Woodlark Island. 



Var. a, Aru Islands ( Trail.). 0. Arruana, Feld. Lep. Frag. p. 24. 



Individuals from this localitj- 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 ^-ith O. Pronoimts, G. E. Gray; but this is generally wanting. 



Var. h, 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- 

 vxire on the under wings. They have generally no golden spots beneath the Avings. They 

 vary also in the outline of the under wings, the outer and anal angles being more aciite 

 in some specimens than in others. Some have the imder wings of a uniform green en- 

 tirely without sj)ots, while others have a range of black spots more or less fully developed. 



Var. c, Waigiou {Wall.). Archideus, G. R. Gray, ?. 



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 no 

 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 aU 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. pi. 11) as from Cape York. One of the Waigiou specimens is 

 the same as Archideus, G. R. G., figured by Boisduval (Voy. de I'Astrolabe, t. 4. f. 1, 2) ; 

 and another, from New Guinea, differs very little from Euphorion, G. R. G. (Brit. Mus. 

 Cat. Lep. pt. 1. pi. 2. f. 3), from North Australia. 



From these facts I am led to conclude that we have here a variable form spread over 

 an extensive area, and kept variable by the continual intercrossing of individuals, which 

 would otherwise segregate into distinct and sharply defined races. The same area is 

 inhabited by many species of birds common to all parts of it ; and just as the bii-ds of 

 Ceram and Amboyna are almost all distinct species from those of New Guinea, so do we 

 find those islands inhabited by the Ornithoptera Priamus, a well-marked and constant 

 species, readily distinguishable in cither sex from the inconstant forms of New Guinea 



