SCOTOPHILUS. 43 



Scotopliillis liesperus, Allen. 



The Western Bat. 

 Fig. 38. Fig. 39. 



Description. — Diminutive. Head small, flat ; face blunt and 

 stout, not hairy. Tragus short, blunt, slightly concave on inner, 

 convex on outer border, causing it to incurve. Thumb small ; 

 nail dull and minute ; foot very small ; wing membranes attached 

 to base of toes. • Interfemoral membrane ample. A small excal- 

 caneal lobe of membrane — the termination of calcaneum blending 

 with the membrane. The tip of the tail is not exserted. Body 

 rather slender. 



The fur is somewhat scanty ; it is thickest on the back where 

 it is of an obscure dirty gray, blending in some individuals to a 

 brownish color — that in front being thinner and of a lighter hue. 

 The main bulk of the fur is of a dark plumbeous, the above- 

 mentioned colors. constituting the tips only^ 



Dentition. 



5 14 15 



Molars — . Canines — Incisors — Canines — Molars _. ^ 34 teeth. 

 5 16 15 



Upper Jaw. — The incisors — both central and lateral — uni- 

 euspid, and of equal length ; the canines moderately developed ; 

 the first premolar is very small, wedged in between the canine 

 and the second premolar, which is large, as in other species of 

 Scotophilus ; the molars as usual. 



Lower Jaw. — The incisors and canines not peculiar ; the pre- 

 molars two in number: the first is small, and is unicuspid, the 

 second larger with an obscure basal cusp. The skull is eminently 

 Scotophiloid, being flat and broad. 



This bat resembles the S. pipistrellus, of Europe, in the con- 

 tour of the head, the shape of the ear and tragus, the smallness 

 and shape of the thumb and nail, the character of the interfemoral 

 membrane, and in the style of coloring. The greater part of the 



