Tube-nosed bats of the genus Nyctimene occur from Celebes on the west to the Santa Cruz Islands on the east. Heretofore, two species (N. albiventer and N. major), each with an endemic subspecies, were known from the Solomon Islands. Both species occur also in New Guinea and on many adjacent islands. A new species of Nyctimene, apparently endemic to the Solomons, and a new subspecies of N. albiventer are named beyond.
Nyctimene is related closely to Cynopterus and the "Cynopterus group" of Andersen (1912:691). Because Nyctimene is a highly specialized bat, Miller (1907:75) placed it in a subfamily separate from that of Cynopterus and its allies.
Andersen (1912:696, 697) placed the species of Nyctimene previously known from the Solomons in two groups, the "papuanus" group and the "cephalotes" group, on the basis of difference in length of forearm and length of maxillary tooth-row. Because of its short forearm (about 58), N. albiventer is in the papuanus group; and N. major, because of its long forearm (about 74), is in the cephalotes group.
Key to Species of Nyctimene in the Solomons
| 1. | Forearm longer than 70; males grayish-brown, females pale gray, |
| N. major scitulus, [p. 825] | |
| 1'. | Forearm shorter than 70; males dark brown, females pale brown, |
| 2 | |
| 2(1'). | Forearm about 65, |
| N. malaitensis, [p. 822] | |
| 2'. | Forearm less than 61, |
| N. albiventer, [p. 818] | |
Nyctimene albiventer
This species occurs throughout New Guinea and on many adjacent islands, including the Bismarck Archipelago and the Admiralty and Solomon islands. The species varies geographically and five subspecies are recognized. The two subspecies in the Solomons resemble N. albiventer papuanus, the subspecies that ranges from eastern New Guinea to New Britain. N. albiventer bougainville occurs in the western chain of islands of the Solomons, whereas another subspecies, named as new beyond, occurs in the eastern chain of islands (see [Fig. 12]).
Sexual dichromatism is striking. As Andersen (1912:690) previously reported, females generally are paler, more brownish than males, which are dark and have a better defined black dorsal stripe.