AMERICAN BATS OF THE GENERA MYOTIS AND PIZONYX 165 



Winff and membranes. — The wing membrane arises from the side of 

 the foot at the ends of the metatarsals. Metacarpals subequal, the 

 third usually but very little longer than the fourth and fifth, which 

 are about equal in length though sometimes slightly graduated. In 

 one or two cases the fifth just exceeds the fourth, in another the third 

 and fifth are equal, exceeding the fourth, while in two other speci- 

 mens the third and fourth are equal, the fifth a trifle shorter, and 

 in another all three are of equal length. In a wing showing slight 

 gradation of these bones, the fourth and fifth fingers are to the 

 third as 84 and 79 to 100; in a second individual having the third 

 and fifth metacarpals equal, the fourth and fifth finger are practi- 



MAP 12. DiSTBIBDTION OF MtOTIS SUBDLATUS ; 1, M. SUBULATDS SDBOLATDS ; 2, M. 



SUEULATDS MELANORHINDS ; 3, M. SUBULATDS LBIBII 



cally equal, and stand in the ratio of 84 and 83 respectively to the 

 third. When the wing is folded, the third metacarpal usually falls 

 short of the elbow by 1 mm. or a little more, and individuals in 

 which this metacarpal equals the forearm are less frequently met 

 with than in Myotis calif oi^nicus. The extreme tip of the tail is free. 

 The fur of the body extends, as in M. calif omicus^ slightly upon the 

 membranes, reaching the level of the distal fourth of the interfemoral 

 above. Below, it extends to a line joining the middle of the humerus 

 and the knee, and from knee to knee on the lower side of the inter- 

 femoral membrane. 



Foot. — The foot is small and delicate, essentially like that of Myotis 

 calif omicv,s. Its length is usually less than one-half that of the tibia 



