Part 9 (2/2)

Troughton (1936:350) considered _Nyctimene bougainville_ specifically distinct from its nearest ally, _N. papua.n.u.s_. Pohle (1953:130) did not examine specimens of either kind, but on the basis of Troughton's description decided that _N. bougainville_ differed only subspecifically from _N. papua.n.u.s_. Laurie and Hill (1954:46) synonymized _bougainville_ and _papua.n.u.s_ with _N. albiventer_. However, Troughton (1936:350) pointed out that in addition to size _bougainville_ differed from _papua.n.u.s_ by having narrower and longer pm3 and pm4. Judging from specimens examined by me, such is the case, and the difference is even more p.r.o.nounced in m1.

Specimens of _N. a. bougainville_ from Kolombangara and Guadalca.n.a.l agree with a paratype of this subspecies from Bougainville. Geographic variation, if present in the population in the western chain of islands (see Fig. 12), is slight and not notable in the series available. Some individual variation was found, especially in the shape of the interorbital region of the skull. An adult male from Kolombangara is unusually dark, almost black; color of the other specimens (all in alcohol) is consistent according to s.e.x.

_Nyctimene albiventer_ from Choiseul and Santa Ysabel is smaller, in all respects, than _N. albiventer_ from Bougainville, Kolombangara, and Guadalca.n.a.l (see Table 3), and therefore may be named and described as follows:

=Nyctimene albiventer minor=, new subspecies

_Type._--Adult male, skin and skull, in good condition (originally stored in alcohol for about one year), no. BSIP 23636, Bernice P. Bishop Museum; from Choiseul Island, British Solomon Islands Protectorate; obtained on 11 March 1964, by Philip Temple, original number 1441.

_Distribution._--Known only from Choiseul and Santa Ysabel islands (see Fig. 12).

_Diagnosis._--Small for _Nyctimene_; wing membranes brown with scattered yellow spots (dried specimens); uropatagium, feet, and ears brown; dorsum of tibia set with hair, ventral surface naked; dorsum of uropatagium spa.r.s.ely set with pale brown hairs, ventral surface almost bare; fringe of hairs along two centimeters of dorsal and ventral surfaces of trailing edge of wing membrane; proximal third of dorsal surface of forearm spa.r.s.ely set with hairs; pelage of back soft and thick, of medium length (about 7); hair on crown and nape short (about 4); well-defined black dorsal stripe, extending from uropatagium to shoulders; skull resembling that of other subspecies of _N. albiventer_ but relatively smaller; zygomatic arch delicate, slender anteriorly; P2 small (see Fig. 14). s.e.xually dichromatic as follows: male--dorsum Hair-Brown, bases of hairs darker; hair on throat spa.r.s.e, medium length (about 6), Hair-Brown; fur along sides of abdomen Drab; female--dorsum having Buffy-Brown cast, some individual hairs Hair-Brown; shoulders Sayal-Brown; hair on throat spa.r.s.e, Hair-Brown on throat and midline of abdomen; sides of abdomen Sayal-Brown.

_Comparisons._--From _Nyctimene major scitulus_, the largest member of this genus in the Solomons, _N. a. minor_ differs in being smaller in all measurements taken; forearm averaging 54.8 as opposed to 73.5; greatest length of skull 28.2 as opposed to 37.0, and females pale brown instead of pale gray.

From nine adults of _Nyctimene albiventer bougainville_ from Bougainville, Kolombangara, and Guadalca.n.a.l, _minor_ differs as follows: averaging slightly smaller in all dimensions; forearm averaging 54.8 as opposed to 57.9; second metacarpal averaging 27.4 as opposed to 28.3; 5th metacarpal averaging 38.5 as opposed to 40.0; condylobasal length 26.7 as opposed to 28.0; length of mandibular tooth-row 10.3 as opposed to 10.9; mandible smaller (see Fig. 14); dorsal stripe fainter.

From _Nyctimene albiventer papua.n.u.s_, known from eastern New Guinea, New Britain, and the Admiralty Islands, _minor_ differs as follows: slightly smaller in most dimensions; forearm averaging 54.8 as opposed to 57.0; length of maxillary tooth-row 8.9 as opposed to 9.8; length of mandibular tooth-row 10.3 as opposed to 11.0; breadth across upper third premolars notably less (7.5 as opposed to 8.4).

_N. a. minor_ differs from _N. albiventer albiventer_ Gray, which occurs about 800 miles to the west of _minor_, in ways made apparent by the description by Andersen (1912:700-701). _N. a. minor_ occurs about 1500 miles eastward of the place from which _N. a. draconilla_ Thomas, a subspecies essentially unknown to me, was named (see Laurie and Hill, 1954:46).

From _Nyctimene sanctacrucis_, known from the Santa Cruz Islands, _minor_ differs as follows: much smaller in all dimensions; forearm averaging 54.8 as opposed to 75; greatest length of skull 28.2 as opposed to 34.5; length of maxillary tooth-row 8.9 as opposed to 12.9.

[Ill.u.s.tration: FIG. 12. Distribution of _Nyctimene albiventer bougainville_ ([BC]) and _N. albiventer minor_ ([LW]).

For names of islands see Fig. 2.]

[Ill.u.s.tration: FIG. 13. Scatter diagram comparing two subspecies of _Nyctimene albiventer_. One individual of specimens thought to be intergrades is as large as specimens of _Nyctimene a.

bougainville_, whereas the other three intergrades are about the same size as specimens of _N. a. minor_. Symbols represent _N. a. bougainville_ ([BW]), _N. a. minor_ ([TW]), and intergrades a.s.signed to _minor_ ([BC]). For names of islands see Fig. 2.]

TABLE 3. Average and Extreme Measurements of _Nyctimene albiventer bougainville_ and _N. a. minor_.

===============+==================+==================+===================

_N. a. minor_

_Intergrades_

_N. a.

bougainville_

MEASUREMENT

Choiseul,

Fauro

Kolombangara,

Santa Ysabel

Guadalca.n.a.l

4 [M], 1 [F]

1 [M], 3 [F]

8 [M], 1 [F]

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