The type specimen of this subspecies is a subadult and is smaller than the specimens examined by me; Andersen (1912:440) gave length of forearm of the type as 137 (as opposed to 164 in adults). He (1912:438) figured the dentition of anceps and described the ways in which it differed from the dentition of atrata. Although he (1912:437) concluded that anceps and atrata represented "two stages of specialization of ... dentition," there apparently are few, if any, dental differences between the two subspecies. Teeth of adults of anceps differ from teeth of the immature type of anceps as follows: in adults the anterior basal ledge of P4 extends onto the labial surface, whereas in the type it does not; and maxillary and mandibular teeth in adults are spaced as in the subspecies atrata (see Andersen, 1912:438, fig. 22) and not crowded as in the type of anceps. Distance between individual cheek-teeth apparently increases with growth of the cranium and mandible.

Adults of P. a. anceps that I examined are darker than the subadult type. The mantle in these adults is black, whereas it is seal-brown in the type (Andersen, 1912:439).

An adult female was lactating when obtained on Bougainville in July (USNM 276928).

Key to Pteropus in the Solomon Islands

1.Premolars having distinct basal ledges; molars 2.5-4.0 wide
2
1'.Premolars lacking definite basal ledges; molars 1.0-2.4 wide
14
2(1).Rostrum unshortened (orbit to anterior tip of nasals about one-third greatest length of skull); dorsal surface of tibiae nearly naked
3
2'.Rostrum shortened (orbit to anterior tip of nasals less than one-third greatest length of skull); dorsal surface of tibiae usually at least partially furred
8
3(2).Forearm more than 128
4
3'.Forearm less than 128
5
4(3).Forearm about 155; venter and dorsum nearly black, mantle pale yellow
P. tonganus geddiei, [p. 798]
4'.Forearm 128-136; venter and dorsum near Mars Brown, mantle Ochraceous or Cream-Buff
P. hypomelanus luteus, [p. 796]
5(3').Mantle dark, russet or cinnamon, not strongly contrasting with color of back
P. admiralitatum solomonis, [p. 796]
5'.Mantle pale, Ochraceous-Buff or Cream-Buff, strongly contrasting with color of back
6
6(5').Mantle Ochraceous-Orange to Ochraceous-Buff, hairs pale basally; forearm 108-111
P. admiralitatum goweri, [p. 797]
6'.Mantle Ochraceous to Cream-Buff, but hairs dark brown basally; forearm 110-122
7
7(6').Length of forearm 110-112
P. admiralitatum colonus, [p. 796]
7'.Length of forearm about 122
P. howensis, [p. 797]
8(2').Forearm more than 145
9
8'.Forearm less than 144
12
9(8).Forearm more than 162
10
9'.Forearm less than 162
11
10(9).Forearm 167-173
P. rayneri grandis, [p. 801]
10'.Forearm about 164
P. rayneri rubianus, [p. 802]
11(9').Flanks and lower belly brightly colored, Burnt Sienna to Sanford's Brown; forearm less than 150
P. rayneri monoensis, [p. 803]
11'.Flanks and lower belly darker, near tawny; forearm more than 150,
P. rayneri lavellanus, [p. 802]
12(8').Pelage of dorsum tricolored; rump brightly colored; forearm 139-141,
P. rayneri rayneri, [p. 800]
12'.Pelage of dorsum bicolored; rump dark; forearm less than 135
13
13(12').Mantle tawny with some Ochraceous-Buff; forearm about 130,
P. rayneri rennelli, [p. 804]
13'.Mantle russet, lacking Ochraceous-Buff; forearm about 121,
P. rayneri cognatus, [p. 803]
14(1').Forearm more than 131; dorsum Tawny Olive
P. mahaganus, [p. 806]
14'.Forearm less than 100; dorsum dark brown
P. woodfordi, [p. 804]

Pteropus Brisson

1762. Pteropus Brisson, Regnum animale ..., ed. 2, p. 153.

Remarks.—More species (seven) and subspecies (12) of Pteropus occur in the Solomon Islands than of any other chiropteran genus. Other kinds of Pteropus, as yet unknown, may live there.