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Papuan snakes of the genus Aspidomorphus have long been taxonomically problematic, but nomenclature within this group has been stable at three recognized species since 1967. Previous genetic work suggested the presence of a number of cryptic but currently unrecognized candidate species in the genus. In 2004, I obtained a series of Aspidomorphus from Sudest Island, Milne Bay Province, Papua New Guinea that were clearly different from currently recognized species, and I describe that species here as A. dimorphus sp. nov. This species exhibits a striking bimodality in color pattern in adults, here termed the “orange morph” and “dark morph”. This dimorphism is not related to sex, and both forms have earlier been shown to be genetically identical. Description of A. dimorphus sp. nov. begins the process of bringing taxonomic clarity to a genus long held in the grip of nomenclatural stasis. It furthermore highlights again the importance of Sudest Island for biodiversity endemism.  

Australo-Papuan snakes of the genus Dendrelaphis have historically been a taxonomically confusing group, with 28 nomina applied to snakes in this region. Recent taxonomic revision has established the presence of nine valid species in this area, though few specimens were examined from across most of the large island of New Guinea. This lacuna, along with unreliable application of names to Melanesian Dendrelaphis in museum collections, means that the ranges of each species remain to be properly resolved on New Guinea and islands immediately to the east. Herein I examine the taxonomic status of Dendrelaphis specimens from outlying large islands in Milne Bay Province, off the southeastern tip of New Guinea, and I find that each of the three large islands of the Louisiade Archipelago, as well as Woodlark Island, contain their own endemic species. Based on hemipenial morphology, three of these species (D. anthracina sp. nov., D. melanarkys sp. nov., D. roseni sp. nov.) belong to the D. papuensis group and the last (D. atra sp. nov.) to the D. punctulatus group. Identification of the first three species requires reassessment and rediagnosis of D. papuensis. Two of the new species are characterized by ontogenetic melanization of animals, and a third is also uniformly black with a white chin when adult, though juveniles are unavailable to determine whether melanization also occurs ontogenetically in that species. Melanesian species of Dendrelaphis are largely diagnosed by unique color-pattern features, and this work identifies additional diagnostic features of color pattern for these species and confirms the critical importance of hemipenial differences in distinguishing among similar-appearing species in this region.  

I describe four new species of Gehyra from New Guinea and immediately adjacent islands. Two of these are giant species that have long been misassigned to either G. vorax or G. membranacruralis; the other two were previously referred to G. oceanica. Each of the new species has a very circumscribed geographic distribution, with one being known from only a single island, a second from a small portion of southeastern New Guinea and immediately adjacent islands, a third from a small archipelago, and the fourth from foothill forest along the northern versant of eastern New Guinea. Three of these species are found only in the Milne Bay Region of southeastern Papua New Guinea, a region previously identified as having a globally high density of narrow-range endemic reptile and amphibian species. These species provide further extension of that pattern by increasing the number of known endemic herpetofaunal species from that small region to 165. Variation in subcaudal shape is taxonomically useful in Gehyra, but its character-state coding must rely on original tails because aberrant development of subcaudals in some regenerated tails could lead to mischaracterization of this feature.