1889.] y LRAL SCIENCES OF PHILADELPHIA. 327 



ital nerve shows* the line from the muscle-mass scarcely elevated. 

 The terminal phalanx of the fourth digit L-shape. 



Vesperugo georgianus. 



Intercostals three in number. Intercosto-humeral from the axilla. 

 The fourth interspace with two long conspicuous predigitals, but no' 

 postdigital. The third interspace with the nerves from the meta- 

 carpophalangeal joints. In a few specimens the two postdigitals 

 arise from a common line Avhich extends parallel to the fifth meta- 

 carpal bone in which case a close resemblance to some forms of 

 Vesj>erus fuseus is seen. The terminal phalanx of the fourth finger 

 as in L. noctivagans. 



Vesperus discolor. 



Intercostals four ; intercosto-humeral at middle of the humerus 

 simple. Internal-cutaneous with two inferior vertical lines. A con- 

 spicuous raised oblique line on mesopatagium from the muscle-mass 

 of the fifth digit. A second oblique line (but smaller than the fore- 

 going) on the fourth interspace. The predigital of this interspace 

 appears from the fourth metacarpal bone 2mm. above the metacarpo- 

 phalangeal joint. 



Vesperus noctula. 



The prebrachium with ridge over position of thickening on tendon 

 of occipito-pollicalis. The mesopatagium retains an oblique fold 

 from muscle-mass and a second from the same in the fourth inter- 

 space. The radiometacarpal region without raised folds from 

 radius. This interspace retains a long predigital from the center, 

 no nerve appearing from the fifth digit itself. The predigital is a 

 small nerve appearing a short distance proximal to the fourth meta- 

 carpophalangeal joint. 



In V. lasiopterus, a closely allied species, the folds from radius 

 near the wrist are raised and the one nearest the wrist conspicuous 

 as in Nxjctinomus and Molossus. The predigital nerve of the fourth 

 interspace showing a disposition as in V. fuseus, viz., to divide high 

 up, the main nerve to be a little convex to the line of the digit, and 

 a large branch to arise from this convexity to be distributed to the 

 membrane. The postdigital as in V. noctula. 



These distinctions of the markings of V. noctula and V. lasiop- 

 terus correlate with others in the auricle, the outer border in the 

 species last named being less well developed. The terminal phalanx 

 of the fourth finger is L-shaped. 



