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Show 248 MR. G. E. DOBSON ON SECONDARY SEXUAL [Mar. 4, hiding the short yellow hair already mentioned. All this yellow fur, both long and short, has a clear and well-defined outline "*. If the shoulder-tufts, so conspicuous in the male, are absent in the female of this species also, as judging from analogy we may expect, we have then three species of Bats of this genus alone possessing secondary sexual characters as remarkable as any known in the class Mammalia. Temminck describes somewhat similar secondary sexual differences in Pteropus macklotii. The male possesses a well-developed odoriferous gland on each side of the neck, covered by a large tuft of stiff unctuous hairs of a bright chestnut colour, contrasting with the surrounding fur. In the female these glands and shoulder-tufts are absent. The same author thus describes the sexual peculiarities of Cynonycteris stramineus, Geoff.:-" Pelage lisse, tres-court et rare; region des cotes et du devant du cou ornes d'un demi-collier roux-dore a. pinceaux de poils onctueux et divergens. Les teintes de ce collier et des pinceaux de poils courtes et divergens qui existent seulement chez le male, varient plus ou moins; l'un des sujets a toutes les parties laterales et le devant du cou d'un teinte jaune-orange encadree par un bande brune. " La femelle manque d'appareil onctueux et de poils divergens aux cotes du cou; ces parties sont d'un jaunatre terne plus ou moins nuance de brun-clair. Le reste du pelage est le meme pour les deux sexes"")*. I have no opportunities here for examining specimens of Bats from the western hemisphere; and very little can be gleaned from the writings of zoologists regarding the occurrence of secondary sexual differences among them. However, Prof. W . Peters, who has contributed so very much to our knowledge of the Chiroptera, has most kindly, in reply to my inquiries, supplied me with some valuable information on this head. In the American continent and its islands the place of the Rhino-lophidae or Leaf-nosed Bats of the Eastern World is taken by the Phyllostomidae, which, though possessing well-developed nasal appendages, are in no other respect connected with the former family, but rather with the Noctilionidae, which they resemble in structure and in their secondary sexual characters. Dr. Peters notes the presence of a gular sac, as in some species of Taphozoi, in the males only of Phyllostoma hastatum and in several species of Molossi, and adds : - " There is nothing more striking amongst American Bats than the development of a large sac in the humeral membrane of Saccopteryx, Peropteryx, Balan-tiopteryx, and other genera; and this organ is only found developed in the males, the females having only a rudiment, which is so small that it has been overlooked by most observers until lately." I have no doubt that, as the species of this little-studied order become better known, as great or, perhaps, a still greater number will * Loc. cit. p. 54. f Loc. cit. p. 85. |