1873.] CHARACTERS IN THE CHIROPTERA. 245 



nipples ; but I observed that they moved about with great energy 

 from one teat to another. Besides the specimens collected I examined 

 about forty other females ; and each had only one young." 



Dr. Anderson saw nothing, he informs me, to lead him to believe 

 that the young obtained nourishment from the pubic teats, save that 

 they occasionally attached themselves to them. Probably the young 

 Megaderms held on to these teat-like organs as every young animal 

 will attach itself to any thing resembling the nipple of its mother. 



We find the next most remarkable secondary sexual differences 

 among the Noctilionidte, especially in the genus Taphozous, Geoff. 

 In this genus the males and females of most species are distin- 

 guished by well-marked secondary sexual characters. 



In Taphozous longimanus, Hardwicke, a species very common 

 about Calcutta, the males are provided with a deep gular pouch, 

 placed between the angles of the mandible, and opening anteriorly 

 by a crescentic margin. This sac contains a yellowish, unctuous, 

 fetid substance, on which the peculiar odour of the animal appears 



Taphozous longiman us. 



in a great measure to depend. In the female no sac exists, but a 

 thin semicircular fold of skin marks the position of the opening as 

 found in the males. In T saccolcemus, Geoff., a similar sexual dif- 

 ference is met with ; but the gular pouch, though relatively much 

 smaller in the female, is not reduced to such a rudimentary con- 

 dition as in T. longimanus. In T. kachhensis, Dobson, the gular 

 pouch is represented in the male by a slightly raised semicircular 

 fold of skin (in the position occupied by the opening of the pouch 

 in other species) and surrounding nakedness of the integument ; 

 while in the female the skin is quite smooth in the same place. 



Thus the transition from species possessing a well-developed gular 

 pouch to those in which it is altogether absent is gradual. 



In Dr. J. E. Gray's " Synopsis of the genera of Vespertilionidse 

 and Noctilionidee" "(Ann. & Mag. Nat. Hist. 1866, p. 92) those 

 species possessing a gular pouch are separated into a distinct genus, 

 under the name of " Saccolaimus." According to this principle we 

 should be obliged to place the males of T. longimanus in one genus, 

 and the females in another ; and, indeed, this is what Dr. L. Fitzinger 

 has lately done. 



