EPTESICUS 



235 



extending to nostril when laid forward, though of the same 

 general form as in E. serotinus ; tip less narrowly rounded off, 

 and flattened or concave portion of posterior border less con- 

 spicuous ; tragus relatively shorter and wider, though not 

 essentially different in form, its greatest width nearly equal to 

 length of anterior border ; transverse striations on inner surface 

 of conch obsolete. Wings and feet essentially as in E. serotinus. 

 Tail slightly longer than in the related animal, extending nearly 

 to head when laid forward, its terminal vertebra free. 



Fur and colour. — In quality the fur resembles that of E. 

 serotinus except that it is softer and more silky in texture, the 

 hairs fully as long as in the larger animal. In distribution it 

 shows no special peculiarities ; dorsal surface of uropatagium 

 thinly furred to about middle instead of on extreme base only. 

 Colour above a rich dark brown, ranging from burnt-umber nearly 

 to seal-brown, the hairs everywhere with slightly darker, faintly 

 slaty bases, those of median dorsal region from crown to base of 

 tail tipped with light glossy ochraceous-buff in evident contrast 

 with ground colour, the light tips most numerous behind shoulders, 

 and forming a noticeable mantle over middle of back ; under- 

 parts rather strongly contrasted light yellowish brown, between 

 the wood-brown and ochraceous-buff of Ridgway, the basal 

 portion of the hairs similar to ground colour of back, the yellowish 

 brown area extending over sides of head and completely encircling 

 base of ear, the line of demarcation between it and the dark 

 brown of upper parts sharply defined along sides of neck. Muzzle, 

 cheeks, ears and membranes blackish. 



Skull. — In general the skull differs from that of Eptesicus 

 serotinus, apart from its smaller size, in a general tendency to 

 greater depth, less elongation, and smoother, more evenly 

 rounded surfaces. Dorsal profile with evident convexity at middle. 

 Lambda not overhanging ; low, ill-defined 

 lambdoid crests curving slightly toward point 

 of contact at middle, the rounded posterior 

 outline of the occiput plainly visible behind 

 them when skull is viewed from above ; 

 sagittal crest essentially absent. Brain-case 

 sub-spherical or broadly ovate in outline, 

 its depth slightly more than half mastoifl 

 breadth ; floor of brain case marked by a 

 wide lateral groove between each cochlea 

 and the median line ; auditory bullae slightly 

 larger than in E. serotinui<. Interorbital fig. 41. 



region relatively less constricted than in Eptesicus wUsonii. 

 E. serotinus, but of essentially the same form ; ^at. size. 



lachrymal swelling present but less noticeable 



than in the larger animal. Rostrum rounded off at sides, with 

 only the faintest trace of lateral concavities ; narial and palatal 

 emarginations essentially as in E. serotinus. Palate showing no 



