DAUBENTON'S, OR THE WATER BAT 



147 



Fig. 14.— Front View of In- 

 cisors AND Canines of 

 Myotis daubenioni (enlarged 

 and diagrammatic). 



horizontal ; that of the face descends in a slightly concave line at an angle 



of about 1 5°. The upper incisors are about equal in size : they are 



short and broad (Fig. 14), the breadth of the 



crowns about equal to their length, bicuspid, 



and with the cusps strongly divergent. The 



two anterior upper premolars are both in the 



tooth-row, but the central, which is much the 



smaller, is slightly displaced internally; its 



conical tip reaches about to the cingulum of 



the posterior. The lower outer incisors are 



oval in section, being about one and a half 



times as long as they are broad, and less than 



half as thick as the canines. 



Geograpliical variation has not been 

 worked out in this species, but there is 

 little doubt that had M. carissima of North 

 America been taken in England, it would 

 have passed muster as daubentoni. 



Dimensions in millimetres (see page 



148). 



Proportionate lengths (males): — Foot, without claws, about -58 of 

 lower leg ; fifth metacarpal, about -94 of third ; lower leg, about -44 

 of forearm and about -33 of head and body. 



' Skull :— Greatest length, 14-5; basal length in middle line, 11; 

 palatal length in middle line, 6 ; from posterior border of m?' to anterior 

 border of canine, about 5 ; same in lower jaw ; greatest breadth at 

 zygoma, 9; posterior breadth, 7-5; breadth between orbits, 7-25 ; 

 breadth at constriction, 4. 



The weight is given by Couch {Zoologist, 1853, 3942) as 97 grains 

 = 6-44 grammes. The same writer (p. 4012) measured one having an 

 expanse of 10-5 inches = 251-20 mm. 



Distingmshing characters :— Of preceding species, the Pipistrelle, 

 which is slightly smaller, can alone be confused with this bat. But the 

 pointed ears ; lanceolate tragus ; little developed post-calcarial lobe ; 

 light under side; large foot, lower leg and calcar; and grizzled upper 

 surface, are quite distinctive. 



Daubenton's Bat, although one of the most abundant and 

 characteristic of British mammals, remained for long unrecog- 

 nised in this country, and affords a striking instance of the 

 light thrown upon our smaller species by the more exact studies 

 of the last years of the nineteenth century. It was first made 

 known to science by the labours of Leisler and Kuhl in Germany. 

 In England, Bingley, who had certainly observed it in its well- 



