INTRODUCTION The scincid lizards of the genus Tribolonotus are generally dull-coloured, armoured, thigmothermic, cryptozoic lizards with several unique features in their morphology and biology. These features include the possession of abdominal glands and volar pores, a vestigial left oviduct, the production of a single egg or young (in all species so far investigated) and an ability to vocalize (in at least one species) otherwise unknown within the family Scincidae. As a result of two recent papers (Zweifel, 1966; Greer & Parker, 1968) the taxonomy of the genus is firmly based, while many aspects of the biology and ecology of various species have been documented. In the course of field work in New Guinea in 1969, as part of Program Β of the 1969 "Alpha Helix" Expedition to New Guinea, I was able to continue earlier observations of Tribolonotus gracilis on Karkar Island. Moreover on Manus Island three specimens of a new species of Tribolonotus were found under piles of rotting coconut husks, a habitat in which Tribolonotus often abound in other parts of New Guinea. I take much pleasure in naming this new species in honour of Dr. L. D. Brongersma for his many valuable contributions to the herpetology of this region. The abbreviations AM and AMNH refer to the Australian Museum and the American Museum of Natural History respectively. Tribolonotus brongersmai spec. nov. Holotype. — AM R30000, an adult male collected by H. G. Cogger, H. C. Dessauer and T. Gobble, circa 9 miles east of Lorengau, Manus Island, Admiralty Group, on August 25th, 1969. Plate 1 is a photograph of the holotype