340 PROCEEDINGS OF THE ACADEMY OF [1889. 



Explanation of Plate X. 



Fig. 1. The wing membrane in Phylhstoma hastatum. Diagramma- 

 tic. 1, prebrachium ; 2, endopatagium ; 3, mesopatagium ; 4 

 ectopatagium (it includes the membrane between all the 

 digits) ; 5, fourth interspace ; 6, third interspace. The 

 dotted line extending from the elbow to the free margin 

 of the membrane represents the limit between the endo- 

 patagium and tbe mesopatagium. I, first digit (thumb) ; 

 II, second digit (index) ; III, third digit ; IV, fourth digit ; 

 V, fifth digit (cpiintus). a, intercostals ; b, intercosto- 

 humeral ; c, internal-cutaneous ; d, fibrous line appearing 

 at the muscle-mass of the fifth finger ; e, one of the pre- 

 digital lines of the fourth interspace;/, longitudinal line 

 in the fourth interspace; g, one of the postdigital lines of 

 the fourth interspace; h, predigital line of the third inter- 

 space ; i, longitudinal line of the third interspace ; j, 

 postdigital lines of the third interspace. 



Fig. 2. Same, of Megaderma frons. A delicate pigmented double 

 contour line is seen crossing the third interspace from the 

 first interphalangeal joint of the third digit to the meta- 

 carpo-phalangeal of the fourth digit. 



Fig. 3. Same, of Natalus stramineus. 



