VESPERTILIO 



129 



best known are, besides V. serotinus, V. nilssoni of Keyserling 

 and Blasius ( = V. borealis auctorum) of northern Europe and 

 Siberia generally to the Arctic circle ; V. murinus of Linnsus 

 ( = V. discolor auctorum) of the temperate portions of the PalcC- 

 arctic region, mainly in moun- 

 tainous districts (for distinctions, 

 see page 140, under V. murinus) ; 

 and Cabrera's V. ochromixtus 

 with forearm only 32 mm., in 

 central Spain and the Balearics. 

 There are representatives in 

 North and South America (see 

 under V. serotinus). 



From those of the preced- 

 ing genera these bats differ in 

 their slightly smaller, narrower 

 ear (Fig. 2, No. 4, p. 7), distinctly 

 longer than broad. The tragus 

 is straight, short, moderately 

 pointed, broadest near the middle, 

 and with a slight forward direc- 

 tion. The wing (Plate IX., 

 Fig. 2, p. 126) is broader than in 

 Nyctalus, but springs from the 

 base of the toes, as in Pipi- 

 strellus. There are fewer teeth 

 (Fig. ii), the small anterior upper premolar being absent, 

 leaving only four teeth, not five, behind the upper canine, and 

 the formula is thus — 



Fig. II.— Diagram of Arrangement 



OF Teeth of VespertUio serotinus. 



(i) Upper and (2) Lower Jaw. 



inc 



I - I 



3-3' 



pm 



2-2' 



3- ■? 



3-3 



The skull (Fig. 4, No. 2, p. 56), as exemplified by serotinus, 

 is heavily built, flattened, larger and altogether stronger than that 

 of Pipistrellus, but, as compared with that of Nyctalus, longer, 

 less massive, and with more rounded brain-case ; the facial region 

 IS angular and concave, the premaxillary gap much less marked, 

 the zygomata expanded, the cranial crests posteriorly prominent, 

 the auditory bullae smaller. In dorsal profile the skull presents 

 nearly a straight line, rising gradually from nose to occiput. 



N 



