The Cyclops Mountains of Dutch New Guinea

Abstract

THE Papuan insect fauna, which is very distinct and very rich in forms, extends outside the island of New Guinea to adjacent islands and to tropical Queensland. By some means it has spread in a south-easterly direction as well, through the Solomon Islands and the New Hebrides as far as the Society Islands in the mid-Pacific. For the last ten years my work has been to follow this Papuan element in the Pacific islands back to the land of its origin; making collections on islands from which we had no material in the national collection, in order to study the distribution of species in that region. In 1936 I spent a year in Dutch New Guinea on an expedition to the Cyclops Mountains to collect for the British Museum. I was allotted a grant in aid of expenses from that Museum, and also from the Percy Sladen Trust. I should like to take this opportunity of thanking the Trustees of both. My collection of insects made in the Territory of Papua in 1933-34 suggested to me that there must have been formerly older land connected with New Guinea, which possibly had not been entirely submerged during the late Cretaceous. For palaeontologists postulate a land mass there which extended somewhere between New Zealand and the Asiatic continent. It is supposed that during the middle Cretaceous New Guinea became separated from Malaysia and later from New Caledonia, and that during the late Cretaceous it was submerged to re-emerge during the Tertiary. The popula? tion from some older land must have spread on to New Guinea, for the greater part of the island is young, being aligned with the Himalayan geanticline. The very rich Papuan fauna and flora cannot have evolved on land raised from the sea during the Miocene-Pliocene; they are basically mainly of Asiatic origin. There is considerable biological evidence to support the supposition of the separation of New Guinea from Malaysia. Certain of the Papuan floristic and zoological groups?frogs and scorpions as well as insects?extend to China through the Moluccas and the Philippines but are not represented on the islands to the west. Those which on the other hand are also found in Malaysia are as a general rule widely distributed and rather rare forms which suggests that they belong to an older fauna. It is satisfactory when biological and geological evidence are not conflicting. If any land in New Guinea has remained dry since an early period it would probably be found north of the main central chain, where there are relics of very old mountains.1 Thus my recent expedition had a two-fold object, to make a systematic collection in one of New Guinea's oldest mountain ranges, and to gather any information concerning the topography of the district which might throw light on problems connected with the origin of its insect fauna. In this respect it was illuminating to learn that the Cyclops