A MONOGRAPH OF THE BATS OF NORTH AMERICA. 67 



Tlic outer border of the iinkle strengthened by a number of trabe- 

 cular lines, which diverge in the endo partagiuin and intersect the lines 

 l^assing between the humerus and the inferior extremity. Fascicles 

 from coraco-brachialis and triceps muscles well developed. In the 

 fourth interdigital space the predigital nerve appears at the distal 

 third of the fifth metacarpal bone, while the postdigital ap])ears from 

 about the middle of the fourth metacarpal bone. Fascial bands marked 

 at the base of the hfth digit. 



Variations. — Two varieties of color are observed in this species — the 

 fawn and the yellowish brown. The first was the one described by 

 Maj. Leconte. This author says: ''Hair light fawn colored, tip with 

 darker, beneath paler." The yellowish brown may thus be described : 

 Hair above light brown at base, darker at tips; below lighter brown 

 not tipped. In some instances the brown tip abov^e assumes a reddish 

 tinge, and the fur beneath becomes almost white. The interfemoral 

 membrane is entirely naked. At the base of the thumb a few brown 

 hairs are found. The membrane to underside calcar in some individ- 

 uals extends obliquely across to the hallical side of foot. As above 

 stated the chin plate is often divided in middle line by a groove. An 

 internarial vertical ridge is sometimes faintly defined. The nostrils are 

 subject to slight variation in size of median part of aperture converting 

 the lunate into an inverted comma-like figure. 



Ruf/w. — The folds seven in number. Between the second and the 

 third, the third and the fourth, the fourth and the fifth, secondary 

 crenulated folds appear. 



Maxillary teeth. — The single maxillary incisor is simjile, conical with 

 a pointed basal cusp. Canine with posterior surface outside of axis of 

 tooth row; palatal surface broad, marked by a longitudinal column 

 which gives to it the appearance of a second cusp. The first molar 

 with protocone raised slightly above the line of the small cingulum, the 

 oblique anterior commissure being absent. An interval exists between 

 the protocone and the posterior V. The anterior V is less than one- 

 half the size of the posterior, both in vertical and bucco-palatal direc- 

 tion. The hypocone is absent. The second molar with protocone as 

 in first molar. The anterior V is much larger than in tooth just named, 

 but relatively smaller than in the corresponding teeth of other genera 

 in the family. The third molar much as in Atalapha. The first lind) 

 of the anterior V alone marked ; the protocone rudimental. 



Mandibular teeth. — Incisors, trifid, not crowded. Canine Avith ob- 

 lique cingulum on lingual aspect with no posterior tubercle. The first 

 premolar obscurely bifid. First and second molars with thickened 

 commissure to heel (liy])oconid) encroaching on the grinding surface. 

 The heel of the third molar a mere rudiment on lingual side. 



The paraconid and metaconid close together, and form a narrow base 

 to the triangle formed by these elements and the protoconid. Tiie 

 hypocouid is much less developed than either of the other elements. 



