﻿5i 



one, the yellow of the under wings is warmer than in 

 Flavicollis, and the apex of the upper wings more rounded. 

 One small specimen of Flavicollis has the apex sharply 

 pointed. Hab. Borneo. 



$ . In Brit. Museum. Agrees in every respect with the 

 Flavicollis figured in my plate, except in the presence of a 

 minute yellow line on the subcostal vein, and that the 

 yellow of the cell and costa does not extend so far 

 inwards — little more than i-3rd. Length of costa 84 mm. 

 Hab. Malacca. 



6* . Brit. Museum. Yellow of Primaries generally 

 redder. Length of costa 54 mm. Hab. Malacca. 

 Another S in same collection has the yellow of Primaries 

 orange tinted. A $ from Penang, costal length 75 mm., 

 presents no other difference. There is no ? of this 

 variety in the Brit. Museum at present. 



These are certainly only local varieties of P. Amphrisius : 

 the greatest differences being that in the <? $ the yellow 

 of the upper wings is much more broadly marked both 

 within and without the cell, but in no one is the yellow 

 within the cell carried so far as in the fig. in our plate — 

 not above i-3rd. In the 2 upper wings the grey stripes 

 and patch close within the cell are almost of the same 

 shape and extent as in the $ , differing therefore greatly 

 from the figure, and from the S of Flavicollis. The same 

 may be said of the under side. 



There are 2 $ $ in the Brit. Museum most near to 

 Ruftcollis, with red collar, and exceedingly rich green- 

 yellow under wings. The markings of the Primaries are 

 only faint stripes, and there is the faintest indication of 



yellow on the discoidal cell, and between the nervures of 

 the costa. These will have to be considered later on as 

 a new variety. A S also appears to belong to it from the 

 same loeality in Borneo (20 miles up the Sundu river, 

 near the Lymbang), differing from the S of P. Amphrysius. 



Reverting once more to the interesting paper of Mr. 

 Skertchley, in the Annals and Mag. of Nat. Hist., vol. iv., 

 p. 218, we find him saying, in connection with the variety 

 flavicollis. 



" The <? has one peculiarity in flight which may be 

 used in courting, and is certainly used on other occasions. 

 In basking among the foliage on sunny riversides, it often 

 flies slowly along moving only its forewings, the hind 

 wings drooping at an obtuse angle to the line of flight, 

 trailing like a rich robe of golden silk. In a freshly caught 

 specimen this position can be easily induced. A furrow 

 in the inner margin of the ? wing allows the notch of the 

 h. w. to be elevated easily without interfering with the 

 partial action of the f. w. In such flight the f. wings only 

 move through a small angle. On the inner margin of the 

 h. w. there is a strong fold fringed with hairs, forming a 

 pouch. In normal flight and when at rest this pouch is 

 closed, but when the h. w. is drooped the pouch opens. 

 It may therefore be a scent pouch, and this particular 

 flight the normal courting flight." 



Skertchly does not mention the peculiar contents of 

 the pouch, or say whether any portion of the cottony 

 material was dissipated after the flight. It would be 

 interesting to know. 



In our plate, fig. 2a, will be found a sketch of the $ 

 anal valves of ruficollis drawn as it appears when quite 

 closed, from a specimen in the author's museum. 



POMPEOPTERA NEREIS. 



Ornithoptera Nereis, William Doherty, Journal Asiatic Soc. Bengal, Vol. lx., Pt. II., No. 1890, p. 30 



This species occurs on an island situated about 80 

 miles west of Sumatra, called Engano. A long line of 

 islands and islets, forming several obvious groups, extends 

 from the great Nicobar island, and chief of the group of 

 that name (that is north of the equator, with a positive 

 west of Sumatra), down to the equator, including in its 

 course the Cocos, Hog, Baniak, and Nias groups of islands ; 

 then south of the equator we find Mintaon, Sebeeroo, 

 Sepora, Poggy, Nassau, and lastly Engano. The latter 

 is 180 miles south of the Nias group, and 210 miles from 

 Java, being situated north of that great island. A con- 

 siderable portion of this long line of islands is usually 

 included in what are called the Sunda Islands, of which 

 we might almost say Sumatra itself is the monarch — being 

 separated only from Java by the Straits of Sunda. Mr. 

 Doherty tell us that Engano is wholly surrounded by deep 

 sea, with a coast protected by its extensive coral reefs 

 from the agencies which are gradually wearing away the 

 other islands. He says " the deep sea that surrounds 

 them swallows up all the alluvium from their streams ;" 

 and " the tremendous surf on their western shore steadily 

 undermines their hills, and under this process the islands 



have long been wearing away." How much this process 

 is delayed or modified by the stupendous volcanic agency, 

 always more or less at work in Sumatra, Java, and the 

 Straits, it would be difficult to say, but this influence 

 must be very great in any case. 



Zoologically Engano is considered by Doherty to be an 

 outlying member of the Nias group, with Javan affinities, 

 and an area of about 120 square miles. It is called 

 Pulo Telanjang, or the Naked Island, by the Malays, 

 because the inhabitants till recently went about in a 

 nude condition. 



The description of the island by Mr. Doherty is very 

 interesting ; and to this, with what the writer in the 

 Tidschrift van Neclerlandsch Indie, or the Journal of the 

 Dutch Indies, says about its people and products, I refer 

 the reader for further information. Mr. Doherty obtained 

 about 10 species of land shells, most of them new, on the 

 island, and only a small collection of Lepidoptera and 

 Coleoptera, in the former of which it would seem there 

 were relatively more butterflies than moths, while among 



