17:127, October 27, type from Bougainville.

1887. Cynonycteris brachyotis, Thomas, Proc. Zool. Soc. London, p. 323, March 15; 1888, Thomas, Proc. Zool. Soc. London, p. 475, December 4, from Fauro.

1889. Xantharpyia brachyotis, Matschie, Die Megachiroptera ... naturkunde, p. 68, from Guadalcanal.

1912. Rousettus brachyotis, Andersen, Catalogue of the Chiroptera ... British Museum, 1:809; 1931, Sanborn, Publ. Field Mus. Nat. Hist., Zool. Ser., 18:11, February 12, from Santa Ysabel.

Remarks.—The specimens from Choiseul, Kolombangara, and Malaita islands provide new records of distribution for Rousettus amplexicaudatus hedigeri (Fig. 3). It was described as smaller than R. a. brachyotis Dobson, which is known from New Guinea, Amboina, and the Bismarck Archipelago (Pohle, 1953:127-128). Andersen (1912:809) gave the range of length of forearm in R. a. brachyotis as 73-81, whereas Pohle (1953:127) gave the length of forearm of the type specimen of R. a. hedigeri (adult male) as 67. Measurements of specimens examined by me indicate that hedigeri occurs throughout the Solomon Islands. Cranial measurements of my specimens and Pohle's type are less than those of R. a. brachyotis (see Andersen, 1912:48).

Sanborn (1931:11) noted that the forearms of three males examined by him were longer than that of a female. Mean and range for length of forearm of males and females listed herein, respectively, are 70.1 (66.0-74.1) and 68.1 (65.0-69.1). Also, each of seven cranial measurements taken by me averaged more in males than in females. Sagittal and lambdoidal crests are more prominent in males than in females.

Table 1. A Summary of Breeding Data for Females of Rousettus amplexicaudatus hedigeri Collected December to June.

As shown in Table 1, adult females obtained in December and January were lactating when captured whereas those obtained in March, April, and June were not. More than half of the individuals collected in March were immature (judging from small size, unfused epiphyses, and lack of wear on teeth). The immature individuals probably had been nursing in December and January.

Pteralopex Thomas

1888. Pteralopex Thomas, Ann. Mag. Nat. Hist., ser. 6, 1:155, February 1.

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

Pteralopex, with one species and two subspecies, is the only megachiropteran genus endemic to the Solomons. Thomas (1888b:475) considered this unusual bat a relic, isolated from the time when pteropodids had cuspidate cheek-teeth. Although two workers (Matschie, 1899:11; Simpson, 1945:54) have synonymized Pteralopex with Pteropus, I regard Pteralopex as a morphologically distinct genus.

Individuals of Pteralopex can be distinguished from all species of Pteropus in the Solomon Islands by the following features: wing membranes originate along dorsal midline; braincase diminutive relative to rest of skull; sagittal crest pronounced; cheek-teeth cuspidate, broad and massive; i2 about 10 times larger than i1; upper canines with well-developed secondary cusp; postorbital process fused with zygomatic arch, forming complete bony ring around orbit.

Andersen (1909a:216; 1912:436) considered the relationships of Pteralopex and Pteropus and concluded that Pteropus pselaphon Lay, 1829, from the Sulphur Islands east of Taiwan, and Pteropus samoensis Peale, 1848, from the Samoan Islands, were the "closest" living relatives of Pteralopex. He stated further that Pteralopex "presents in fact scarcely a single character which is not either developed to a certain extent or at least distinctly foreshadowed in Pteropus pselaphon, pilosus, tuberculatus, or leucopterus." In summary, Andersen thought several species of Pteropus had undergone evolutionary development resembling that in Pteralopex, and that the latter, with its massive, cuspidate cheek-teeth, could be considered a highly modified Pteropus. For this hypothesis to be plausible, one must assume that the originally complex cheek-teeth of pteropodids became simple and, at least in the case of Pteralopex, secondarily became complex once again. According to present-day theory of evolutionary development, his hypothesis is improbable. Thomas (1888b:475) probably was correct when he considered Pteralopex an isolated relic.

Although Pteralopex usually is listed after Pteropus in phylogenetic arrangements (see, for example, Sanborn, 1931:21; Pohle, 1953:129; Laurie and Hill, 1954:40), I have placed Pteralopex before Pteropus.

Pteralopex atrata

Two subspecies of Pteralopex atrata (P. a. atrata and P. a. anceps) have been named; specimens of both are rare in museum collections. Thomas (1888a:155) described adults of