NYCTALUS 



247 



the region on each side of it flat or slightly depressed ; lambdoid 

 crest high, curved abruptly forward at point of junction with 

 sagittal crest ; floor of brain-case with small but evident lateral 

 pits, well denned anteriorly but communicating posteriorly with 

 vacuity between cochlea and basioccipital ; auditory bullae well 

 developed but of moderate size, the transverse diameter about 

 equal to distance between bullae. Interorbital region deeply 

 constricted, short hour-glass shaped, the lachrymal region widen- 

 ing abruptly to a breadth nearly equal to that of brain-case, and 

 forming a slight though evident tuber- 

 cular projection over anterior rim of orbit ; 

 rostrum squarish, somewhat narrower 

 anteriorly than posteriorly, the oval or 

 ovate narial emargination extending back 

 to level of lachrymal foramen ; rostral 

 depth at front of orbit about equal to 

 distance from orbit to front of inner 

 incisor ; anteorbital foramen small, over 

 space between large premolar and first 

 molar, lachrymal foramen slightly above 

 and behind it, on orbital rim. Palate 

 rather short, owing to the large size of 

 the anterior emargination, the posterior , """ "'. , 



, ,, .... ° -. , ... ■ i ii j? Nyctalus noctvZa. 



edge ot which is on level with middle ot Nat. size, 



large premolar, rather evidently concave 



laterally, less so longitudinally. Posterior extension of palate 

 nearly parallel sided, its width at level of posterior edge of third 

 molar slightly less than length ; hamulars barely turned inward ; 

 median spine large, acute. Mandible robust, noticeably deeper 

 at symphysis than immediately behind tooth-row ; posterior 

 portion rather low and long, the height of coronoid process 

 above alveolus less than least length, the upper border sloping 

 gradually from coronoid to articular process ; angular process 

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

 axis directed rather abruptly outward, its distal extremity 

 obliquely widened. 



Teeth. — Relatively to size of skull the teeth are large, though 

 the cusps are rather low. Inner upper incisor slender, with 

 slightly developed cingulum, its crown area barely one quarter 

 that of canine, the nearly terete shaft directed obliquely inward, 

 its apex extending slightly beyond level of cingulum of canine, 

 its secondary cusp small but evident, situated on postero-external 

 surface of shaft ; outer upper incisor with crown area distinctly 

 greater than that of inner tooth, the shaft deeply concave, its 

 concavity directed outward and backward, the main cusp lying close 

 against secondary cusp of inner tooth, the well-defined se-.iondary 

 cusp relatively much larger than that of inner incisor, cingulum 

 well developed, bearing a small but distinct antero-external cusp 

 on opposite side of concavity from secondary cusp. The two 



