XXll INTEODtrCTION. 



shaped wart- like elevations and grooves. In the long-tongued GIos- 

 sopliagm (Plate XXVII.) the groove in the centre of the lower 

 lip serves as a channel for the tongue, which can be thrust out be- 

 tween the lower canines without necessarily opening the mouth. 

 The form of the lips is exceedingly peculiar in Noctilio, and will 

 be found described at p. 395, and figured in Plate XX. 



In the Megachiroptera the form of the lips is generally less vari- 

 able, but in the genus Epomopliorus (the species of which live on juicy 

 fruits) they are exceedingly expansible, forming deep folds and 

 pouches especially in adult males, and in E. {Hypsignailius) mon- 

 strosus are most remarkably lobed in front. The nakedness of the 

 lips and complete absence of a fringe of hairs is very characteristic 

 of all fruit-eating Bats, and probably always distinguishes them 

 from the insectivorous species which they may resemble in the form 

 of their teeth and in other respects. 



The inner margins of the lips in nearly all the frugivorous species, 

 whether belonging to the suborders Megachiroptera or Microchiro- 

 ptera, are fringed with numerous long conical papillae. 



In all Bats palatal ridges are more or less well-defined, but are 

 largest in Megachiroptera, and reach their highest development in 

 the genus Epomopliorus, where their form and arrangement is 

 characteristic in each species (see p. 5, and Plate II. figs. 1-6). 



The oesophagus is narrow in all species, and especially so in the 

 sanguivorous Desmodontes. The stomach presents two principal 

 types of structure, which correspond respectively to the two great 

 divisions of the order, the Megachiroptera and the Microchiroptera. 

 In the former the pyloric portion is much produced and often folded 

 upon itself; in the latter the same part is very short and the pyloric 

 aperture close to the entrance of the oesophagus, the cardiac portion 

 being expanded into a simple globular or oval sac, or greatly elongated, 

 forming an intestiniform csecum, as in the group Desmodontes. 



The complex form of the stomach in the frugivorous Megachiro- 

 ptera is comparable to that of the Ruminantia, while the insecti- 

 vorous Microchiroptera resemble the Carnivora in the simple form 

 of the same organ. 



In Pteropus the oesophagus opens into a pyriform pouch, to the 

 left of which the cardiac portion is expanded longitudinally, but is 

 not contracted in the middle ; behind, a constriction opposite the 

 entrance of the oesophagus indicates externally the commencement 

 of the pyloric portion, which is immensely elongated, resembling a 

 large colon, and is folded to the left upon itself, so that externally 



