146 Proceedings of the Royal Physical Society, 



It was, however, a rare bird, although found at various places along the 

 rocky coasts of Britain, and appeared to be abandant in Wigtonshire. 

 It was found in the island of Mull, in Skje, and at St Abb's Head, 

 on this side of the island. The account of the migration of the swift was 

 also very interesting. It seemed to have been rather an early one ; at 

 least this bird is generally described as leaving us about the beginning or 

 middle of August. 



IV. (1.) Notice of a New Leaf Insect. By Andrew Murray, Esq. 



Mr Murray exhibited a beautiful photograph of the under side of a 

 butterfly, in every respect exactly like a dead leaf. He had received it 

 from Dr William Traill, H.E.I.C., presently stationed at Russelcondah 

 in the Madras Presidency. Dr Traill, in transmitting the photograph, 

 writes : — u I wished to have sent you a curious insect, brought to me as a 

 leaf insect. In Singapore and the Straits, where a variety of these 

 singular forms are found, they are all allied to the Osthoptera^ or the 

 genera Mantis, Empusa, Phasma, &c. I am a good deal accustomed to 

 their various forms, but on this occasion 1 was completely taken in, and 

 until the animal moved, I thought it a dead leaf. To my surprise, I 

 found it to be a butterfly ! When at rest, its two anterior wings (which 

 are slightly falcate at the tip) were pushed forward in front of its head, 

 so that a central line on them exactly met a similar central line on the 

 posterior wings, so as to simulate the mid-rib of a leaf. The four wings 

 so disposed presented the most exquisite resemblance to an autumnal leaf; 

 and even the veining is represented with wonderful fidelity, especially if the 

 animal is held two or three feet from the eye of the spectator. A remorse- 

 less rat one night carried off the insect, along with the pin on which it 

 was impaled ; but I had a few days before got a photograph of it made, 

 which I now send you. It is, however, very far from giving a just idea 

 of the original. The upper side of the wings were most brilliantly 

 coloured, but I do not remember exactly what colours." Of course, these 

 brilliant colours will only be seen when the insect is in motion ; when at 

 rest, and more exposed to danger, the folding back of the wings conceals 

 them, and shows only this extraordinary resemblance to a leaf. The re- 

 semblance is every whit as great as that exhibited by the leaf insect 

 proper (Phyttium), only being that of a dead leaf instead of a green one. 

 The insect appears to be undescribed, and, from its powers of concealment, 

 is no doubt rarely captured. Most butterflies have lines on the anterior 

 and posterior wings, often both above and below, which become continuous 

 when placed in juxtaposition ; and there are several exotic species which 

 have a line similar to the mid-rib of a leaf figured upon the under side 

 of the wings ; but none hitherto described at all approach the present in 

 its close resemblance to a leaf, both in shape, veining, and shading. It is 

 impossible, from merely a photograph of its under side, to determine its 

 genus ; but from its falcate anterior and single-tailed posterior wings, it 

 probably belongs to the same group of the Nymphalidce as Amathuda 

 and Zeuxidia. 



(2.) Description of New Sertulariadse, from the Coast of California. 

 By Andrew Murray, Esq. (With two Plates.) 



The interest which attaches to the existence of closely allied 

 forms in far distant regions induces me to publish the follow- 



