142 



VESPERTILIONID^— MYOTIS 



ing to the breadth of the face. The nostril opens without 

 prolongation sub-laterally, the aperture being crescentic. 



The ear (Fig. 2, Nos. 5-8, p. 7) is long and oval, distinctly 

 longer than broad ; the outer margin terminates anteriorly below 

 the base of the tragus, or very slightly in front of it, and does not 

 run forward towards the angle of the mouth ; the internal basal lobe 

 is angular. A number of cross-folds or pleats running horizontally 



across the ear, near the outer margin, 

 are characteristic of the various species, 

 but are often inconspicuous after death. 

 The tragus is long, narrow, and gene- 

 rally attenuated to a point. 



The foot, lower leg, and calcar are 

 of variable size and development. 



The wing is broad, or moderately 

 so, the fifth metacarpal being slightly 

 longer than or about equal to the third ; 

 the attachment may be from a little 

 above the ankle, to the base of the 

 toes. The post-calcarial lobe is poorly 

 developed. The tail is rarely so long 

 as the combined head and body. 



The skull varies in strength accord- 

 ing to the size of the species : it has 

 usually a rounded brain-case, elevated 

 above the facial region, which is narrow, 

 depressed, and markedly saddle-shaped: 

 the premaxillary gap is developed to a 

 degree about intermediate between that 

 of Nyctalus and Vespertilio ; the zygo- 

 mata are flattened, the auditory bullae 

 moderately developed. 



The number of teeth (Figs. 8, p. loi, 

 13, and 16, p. 174) is increased to 

 thirty-eight by the addition of a third premolar in each jaw and 

 side, so that the formula is — 



Fig. 13. — Diagram of Arrange- 

 ment OF Teeth in Genus 

 Myotis. 



(l) Upper and (2) Lower Jaw. 



c . pm ~ — -'' 



w?— ? = 38. 

 3-3 



3-3 i-i' ^ 3-3 



The upper incisors are sub-equal, their points generally diver- 



