AMERICAN BATS OF THE GENERA MYOTIS AND PIZONYX 39 



incisors) usually more than 5.6 (5.4 to 6.2) ; ear reaching nostril 

 when laid forward, its height from meatus usually 13 to 15 mm.; 

 wing from the side of foot, which is large, exceeding one-half the 

 tibia (ratio of foot to tibia ranging from about 53 to about 55.7) ; 

 calcar without keel ; hairs of back with long glossy tips which impart 

 to the pelage a conspicuous metallic sheen. Skull with gradually 

 rising forehead and broad brain case which is usually not provided 

 with a distinct sagittal crest. Upper molars with full complement 

 of secondary cusps and ridges, but with a narrow, inconspicuous 

 and sometimes incomplete cingulum on inner border of crown. 



Ears. — The ear is of moderate length, when laid forward reach- 

 ing to the nostril ; its anterior edge is convex, becoming nearly 

 straight in the upper third to the bluntly rounded tip; below the 

 tip the .external margin is slightly concave or nearly straight in 

 the upper half, then convex in the lower half which forms a pro- 

 jecting, but not abrupt, shoulder. The tragus is about half the 

 total height of the ear (8:15 mm.). At its outer base is a small 

 rounded lobe, marked off by a shallow notch. Above this point and 

 opposite the inner base is the widest region. The inner margin of 

 the tragus is nearly straight, the outer very slightly convex, and 

 faintly crenulate to the narrowly rounded tip. 



'Wing and Tnemhrames. — The wing membrane arises from the side 

 of the foot near the distal end of the metatarsal. The third to fifth 

 metacarpals are graduated, the third longest, the fourth slightly 

 shorter, the fifth still shorter. The basal phalanges and total length 

 of the digits are likewise graduated in the same order. Taking the 

 third finger as 100, the fourth and fifth fingers are, respectively, as 

 86 and 80 (60:52:48 mm.). When folded, the third metacarpal 

 usually falls short of the elbow by about 2.5 mm. The extreme tip 

 of the tail is free. Uropatagium with minute hairs along the free 

 border. These hairs are few and widely scattered, very inconspicuous. 



Foot. — The foot is rather large, the ratio of its length to that 

 of the tibia ranging from about 53 to nearly 56. Calcar long (about 

 17 mm.), exceeding in length the free border of the interfemoral 

 membrane, terminating in a minute lobule ; its free edge quite with- 

 out indication of a keel. Outer toe a little shorter than the others. 

 A slight web between bases of toes; terminal joints with a few very 

 small stiff hairs. 



Fur and color. — The pelage is rather full, but not fleecy, long and 

 fine above, the longer hairs attaining a length of about 9 to 10 mm. 

 On the ventral surface of the wing membrane the fur extends thinly 

 from the knee to the distal three-fourths of the humerus. The inter- 

 femoral membrane is thinly haired about to a line joining the knees. 

 Characteristic are the long glossy tips of the dorsal hairs which 



