240 



CHIROPTERA 



Skull. — The skull combines the short, smooth brain-case of 

 Eptesicus nils8onii with the broad, flat rostrum of E. serotinus, but 

 differs conspicuously in aspect from both in the very deep, 

 Nyctalus-like narial and palatal emarginations. Dorsal profile 

 essentially straight from nares to rounded, not overhanging 

 lambda. Sagittal crest obsolete ; lambdoid crest low but evident. 

 Depth of brain-case at middle decidedly more than half mastoid 

 breadth ; floor with wide conspicuous slit between cochlea and 

 basioccipital ; a flattened pit-like depression at front of each slit ; 

 auditory bullae moderately large, their trans- 

 verse diameter about equal to space between 

 them. Interorbital region broadly hour-glass 

 shaped, flattened above ; edge of orbit from 

 lachrymal region nearly to most constricted 

 portion distinctly and irregularly swollen. 

 Dorsal surface of rostrum flattened, with broad, 

 shallow lateral depressions ; narial emargina- 

 tion broadly triangular, its apex extending 

 back to level of lachrymal region ; rostral depth 

 at front of orbit equal to distance from orbit 



Ves P e,-tiKo Zurinm. to f ront of inner incisor J . anteorbital foramen 

 Nat. size. moderately large, over point of contact between 



large premolar and first molar ; lachrymal fora- 

 men directly behind it on inner rim of orbit. Palate broad and 

 short, noticeably concave both laterally and longitudinally, the 

 anterior emargination large, much wider than deep, but extend- 

 ing back to level of middle of premolar ; posterior extension of 

 palate parallel sided, its length slightly greater than width 

 behind molars ; hamulars slightly bent inward ; median spine 

 well developed. Mandible robust, much deeper at symphysis 

 than behind tooth-row, the coronoid process low (height less than 

 least width of posterior section) with gradually sloping upper 

 border ; angular process rather slender, its extremity slightly 

 curved inward. 



Teeth. — While in general resembling those of the European 

 species of Eptesicus, especially those of E. nilssonii, the teeth of 

 Vespertilio murinus show certain notable peculiarities. Inner 

 upper incisor similar to that of Eptesicus serotinus when viewed 

 from in front, but with well developed postero-basal cusp which 

 in some specimens rises nearly to half the height of main cusp, 

 producing a distinctly trifid tooth ; outer incisor with crown area 

 slightly less than that of inner, the cusp rising nearly to middle 

 of shaft of inner tooth ; secondary cusp slightly developed ; 

 position of incisors relatively to tooth-row about as in E. nilssonii. 

 Lower incisors as in E. nilssonii. Upper canine with transverse 

 diameter slightly greater than longitudinal diameter, the reverse 

 of the condition in the two species of Eptesicus ; lower canine 

 with same peculiarity in outline of crown though to a less degree. 

 Upper premolar with longitudinal diameter of crown relatively 



