146 Proceedings of the Royal Physical Society, 
It was, however, a rare bird, although found at various places along tlie 
rocky coasts of Britain, and appeared to be abundant 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.LC., presently stationed at Russelcondah 
in the Madras Presidency. Dr Traill, in transmitting the photograph, 
writes : — " 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 Orthoptera^ or the 
genera Mantis, Empusa, Phasma, &c. I am a good deal accustomed to 
their various forms, but on this occasion I 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 l^eld two or three feet from the eye of the spectator. A remorse- 
less rat one night carried oif 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 {Phyllimn), 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 jjresent 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 Amathusia 
and Zeuxidia. 
(2.) Description of New Sertulariadse, /rom tJie 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- 
