PLASTIC CHAKACTEK9. XXUl 



6. Tympanic bodies. 

 Alwajs annular, but the ring varying a little In breadth (rather 

 broader than usual in liousettus, Dobsonia, Eouyctey-is). The only 

 peculiar modification is the development of a short bony auditory 

 meatus in Eidolon (fig. 1, p. 3 ; cf. Miller, 'Families and Genera 

 of Bats,' p. 55, fig. 7 B), a genus closely related to liousettus. 



7. Facial axis. 



Normally the facial axis if projected backward is nearly parallel 

 witli the basicrauial axis, i. e. the former forms an angle with the 

 latter of not much less than 180 degrees, and the line of the alveolar 

 margin of the upper tooth-row if continued backward passes through 

 the lower edge of the occipital condyle or even somewhat below the 

 condyle ; such is the case, with rare exceptions, in all genera of the 

 Epomophorus and Cynopterus sections (ex. fig. 36, p. 515, and tig. 48, 

 p. 588). In the Eousetto-Pteropine section generally the face is 

 more distinctly, sometimes even very conspicuously detiected on 

 the basicrauial axis, so that when the rostrum is kept horizontal 

 the axis of the brain-case points obliquely backward-and-downward, 

 and the posterior projection of the alveolar line passes through the 

 middle or upper margin of the occipital condyle (ex. fig. 1, p. 3 ; 

 fig. 6, p. 62) or even through the middle of the supraoccipital 

 (fig. 3, p. 49 ; fig. 18, p. 404). The maximum of facial deflection 

 is seen in the majority of Macroglossincn, in which the face is bent 

 downward to such degree that the alveolar line if continued pos- 

 teriorly would pass through the brain-case considerably above the 

 lambdoid crest (fig. 70, j). 748). 



As a general rule the deflection of the face is greatest in genera 

 or species with weak dentition ; thus it is considerably greater in 

 the narrow-toothed Stenonycteris (fig. 3, p. 49) than in typical 

 Rousettus (fig. 2, p. 17); in Pteropus the deflection is always 

 noticeable, but least so in the heavy-toothed species (ex. fig. 15, 

 p. 302, Ft. p)selaphon), and unusually great in the small- and 

 narrow-toothed Ft. scapulatus (fig. 18, p. 404) and Ft. woodfordi 

 (fig. 19, p. 408) ; the only Epomophorine genus with conspicuously 

 deflected facial axis is the very weak-toothed Flerotes (fig. 28, p. 484), 

 and the only Cynopterine genus with similarly deflected face is the 

 weak-toothed 8p>ha;)-ias (fig. 60, p. 672) ; within the subfamily 

 MacrocjlossincB the deflection is smallest in the relatively strong- 

 toothed Eonycleris (fig. 66, p. 730), greater in Meyalaglossus (fig. 68, 

 p. 739), which in the degeneration of the dentition is transitional 

 between Eonycleris and Macroglossus, very great in all other 

 genera, all of which are characterized by unusually narrow or 

 small cheek-teeth. 



8. Mandible. 

 The heavier the dentition, the broader and deeper and more 

 vertically ascending is the coronoid process of the mandible, the 

 stronger its angular process, and the higher above the alveolar line 

 its condyle ; the weaker the dentition, the narrower and lower and 

 more backwardly sloping is the coronoid process, the feebler the 



