332 PROCEEDINGS OF THE ACADEMY OF [1889. 



digit. A small oblique fold concealed beneath lateral border of the 

 muscle-mass of the fifth digit. 



In the fourth interspace the general arrangement as in Mormoops. 

 A faint attempt at the formation of a logitudinal line seen. The 

 postdigital arises from the end of the proximal third of the fourth 

 digit. The predigital and postdigital unite. 



The interfemoral membrane as in Mormoops, the branches from 

 the thigh and leg inconspicuous or absent. 



Tips of digits much as in Molossi. 



Natalus stramineus. (Plate x, fig. 3.) 



Endopatagium with seventeen intercostal lines. Intercosto-humeral 

 attached to proximal third of the humerus ; it divides once before 

 reaching line of the elbow whence it passes almost to margin of the 

 membrane. 



The internal cutaneous with seven conspicuous vertical inferior 

 lines ; one doubtful superior oblique present. Above the main 

 nerve two lines run parallel to it. One of these ends abruptly 

 whence a vertical line extends inferiorly. A rectangular disposition 

 of lines. The second passes to the metacarpo-phalangeal joint. 



The fourth interspace with pre- and postdigital nerves symmetri- 

 cally disposed. Each nerve arises high up on the metacarpal. 



The angle of this interspace occupied by a sharply defined fold 

 An apparent attempt at the formation of a longitudinal line is the 

 third interspace opposite the first phalanges. The terminal phalanges 

 simple small and inconspicuous. 



Thyroptera bicolor. 



Intercostals five and reach side of trunk. Intercosto-humeral 

 near axilla, simple unbranched. Internal cutaneous without 

 superior oblique. The line is intersected by four verticals, nine 

 toward radiocarpal angle. 



A delicate line appears at the radius near the elbow and ends on 

 the mesopatagium near its middle. This appears to be homologous 

 with the line above the internal-cutaneous in Vespertilio, Ves- 

 perugo, etc. 



Fourth interspace. Three predigital lines. All are small, the 

 lowest the largest and arises from the digit at distal fifth of fifth 

 metacarpal bone. Near the angle of the interspace but to the side 

 of the fifth digit is a large nerve which appears to be the same as 

 the postdigital, which in place of arising near or at the apex as in 



