228 



CHIROPTERA 



Slcull. — General aspect of skull robust and flattened, with 

 widely spreading zygomata, but rather narrow brain-case and 

 rostrum. Dorsal profile rising gradually from nares to over- 

 hanging lambda, essentially straight throughout, though with 

 slight concavity over lachrymal region. Ventral profile very 

 slightly elevated posteriorly. Brain-case ovate in general outline, 

 narrower than in Nijctalus nociida, the straight, well developed 

 lambdoid crests which form its posterioi' border meeting in median 

 line almost at right angles, depth at middle about half mastoid 

 breadth ; sagittal crest low but evident, the region at each side 

 of it not depressed ; floor of brain-case smooth, with no evident 

 ridges or depressions, a very narrow slit between cochlea and 

 basioccipital ; auditory bullie small, the transverse diameter con- 

 siderably less than distance between bulla?. Interorbital region 

 moderately constricted, hour-glass shaped, the lachrymal region 



decidedly less wide than brain-case, 

 with slight tubercular projection close 

 to anterior rim of orbit ; rostrum 

 flattened, with shallow but evident 

 lateral concavity on each side, dis- 

 tinctly narrower anteriorly than pos- 

 teriorly, the narrowly obovate narial 

 emargination extending about half 

 way back to level of lachrymal fora- 

 men ; rostral depth at front of orbit 

 less than distance from orbit to outer 

 incisor ; anteorbital foramen less i*e- 

 duced than in Ni/ctalus noctula, its 

 posterior border over region of con- 

 tact between large premolar and first 

 molar, lachrymal foramen directly 

 behind it, on inner side of orbital 

 rim. Palate long and narrow, slightly concave both laterally and 

 longitudinally, the anterior emargination small, squarish, extend- 

 ing back to level of middle of canine. Posterior extension of 

 palate nearly parallel sided, though narrowing a little posteriorly, 

 its width at level of posterior molar considerably less than its 

 length ; hamulars slightly turned inward ; median spine well 

 developed. Mandible robust, but with lower border nearly 

 parallel to alveolar line ; posterior portion high in front, low 

 behind, the height of coronoid process above level of alveolar 

 line about equal to horizontal diameter, the upper border sloping 

 abruptly from coronoid to articular process ; angular process 

 moderately long, about on level with alveolar line, its main axis 

 directed gradually outward and downward, its distal extremity 

 slightly expanded and hooked upward. 



Teeth. — -Relatively to size of skull the teeth are large and 

 robust, rather more so than in Nyctalus noctula. Inner upper 

 incisor about half as high as canine, its crown area about one- 



FlG. 40. 

 Eptesieus serotinus. Nat. size. 



