Besides the butterflies which I have mentioned as frequenting the open downs, I found on this and subsequent occasions some forest-loving species of great interest on the skirts of the wood at the peak. The one which gave me most pleasure was a large dark grey species of Delias with yellow blotches on the underside, Delias ithiela Butler. This insect was originally described by mistake as occurring at Penang, and is a dark form of a common Himalayan butterfly, Delias horsfieldii, which occurs from Kulu in the north-west as far as Sikkim. It may probably be the same as D. belladonna, a species which occurs in China and East Tibet, but is so variable that until now I had been unable to separate the different forms of it which occur at various elevations in Sikkim, most abundantly by the side of streams in deep tropical gorges where it sits on wet sand or stone, but sometimes in the forest from 6,000 to 8,000 feet. The female, which is so rare that it was unknown to the describer, I had never been able to find in Sikkim, but here on the skirts of this little wood I found both sexes fairly abundant, though very different in their habits, as in their habitat, from the Sikkim insect. Here they emerge from the dense foliage of the tree-tops and sail about with a gentle soaring motion in the sun, continuing their flight even when mist and rain come on, and frequently settling on the blossoms of a Dipsacus and of a white-flowered shrub, Viburnum coriaceum, which attracted them. Though they are somewhat shy, I was enabled by patiently watching these flowers to catch a good series of this beautiful insect. I saw them also' in and near similar patches of forest in other parts of the hills above 4,000 feet*
Another insect which I was quite unprepared to find there was more rare. It is the same as, or almost identical with, Lethe maitrya, a glossy dark brown Satyrid which was first discovered in the North-West Hima¬ layas at over 9,000 feet elevation, and afterwards found abundantly by me on the Tonglo range in Sikkim at 9,000 to 12,000 feet. Here it occurred as low as 5,000 feet but must be rare, as I only took four or five specimens and no one else has recorded its existence on the Khasias. A few large and beautiful Papilios were occasionally seen hovering over the tree-tops in this wood, and flying before the wind over the ridge, whilst Danais tytia, a species which occurs in the North-West Himalayas and Japan, was also not uncommon. On a piece of marshy ground between the station and the farm I also took one or two specimens of a Clouded Yellow, Colias Fieldii, which, though peculiar to the Himalayas, and even common there both in the north-west and in Sikkim, frequents much higher elevations than it does at Shillong, and is typical of one of the most Arctic forms of insect life, of which some species occur in the highest latitudes. A similar straggler is found in the form of Colias nilghiriensis, a near ally of our English Pale Clouded Yellow, on the tops of the hills of Southern India, but nowhere in the country between there and the North-West Himalayas. Though the species varies extremely over the greater part of its wide range from England to Japan, and has been divided into many supposed species, yet none of its forms seems to be so well
I published an account of this butterfly and its varieties in the Annals and Magazine of Natural History for February, 1886.
