1931. Pteropus howensis Troughton, Proc. Linn. Soc. New South Wales, 56:204, June 24, type from Lord Howe Islands (Ontong Java); 1950, Sanborn and Nicholson, Fieldiana:Zool., 31:329, August 31.
Specimens examined (one male, three females, and two sex unknown; two embryos in alcohol).—Liuniuwu, Lord Howe Islands (Ontong Java) in August, USNM 278703-6, USNM 279715-6.
Measurements.—Average and extreme measurements of one male and three females are as follows: Length of head and body, 185.2 (176-196); hind foot, 34.5 (33-36); ear, 21.5 (21-23); forearm not measured [broken in all specimens examined]. Cranial measurements of a male and a female are, respectively, as follows: Greatest length of skull, 55.3, 53.8; condylobasal length, 54.2, 52.8; palatal length, 26.7, 26.0; zygomatic breadth, 30.6, 29.9; breadth of braincase, 19.9, 19.2; breadth across first upper molars, 14.3, 14.3; length of maxillary tooth-row, 20.7, 19.6; length of mandibular tooth-row, 23.1, —.
Remarks.—Apparently Pteropus howensis is confined to Ontong Java (Lord Howe Islands) located northeastward of the main body of islands that constitute the Solomon Archipelago (see [Fig. 5]). According to A. J. Nicholson, who collected the specimens listed above, P. howensis is not abundant in Ontong Java. He related this circumstance to the fact that these small islands are nothing more than parts of a coral atoll used almost entirely for the production of coconuts (see Sanborn and Nicholson, 1950:329).
Specimens of Pteropus howensis deposited in the U. S. National Museum agree well in most ways with the original description of the species by Troughton (1931:204-205). Slight variation in color is evident; in two specimens, the mantle, just posterior to the ears, is Ochraceous-Buff.
The relationship of this species to other kinds of Pteropus known from Melanesia is not clear. Troughton (1931:204, 206) compared P. howensis with P. hypomelanus and P. admiralitatum and found that it resembled each of them. Tate (1934:2) noted that the skull of P. admiralitatum goweri was similar to that of P. howensis in structure. The latter species is, however, larger (length of forearm 122 according to Troughton, 1931:205) than any subspecies of P. admiralitatum (length of forearm 108-112). Also, the cheek-teeth of P. howensis that I have studied are relatively larger than those of either P. hypomelanus or P. admiralitatum. Furthermore, in P. howensis there is a small but distinct cusp located medio-posteriorly on P4 (most noticeable in young individuals) that is more reduced or undeveloped in specimens of the other two species. Cheek-teeth of P. howensis resemble those in a dull-colored specimen of P. tonganus from Fiji Island with which I compared the specimens listed above.
Weights and crown-rump lengths of the two embryos (in an advanced stage of development) examined were 20 and 29 grams and 43 and 51 mm. (apparently these are the specimens listed by Sanborn and Nicholson, 1950:329).
Pteropus tonganus
Pteropus tonganus has at least three subspecies, one of which has been recorded from the Solomons. The species ranges from a small island off the eastern coast of New Guinea, where there is an endemic subspecies, eastward to Tonga and the New Hebrides (Laurie and Hill, 1954:33-34). Felten (1964a) recently has reported on the species in the New Hebrides.