1889.] NATURAL SCIENCES OF PHILADELPHIA. 315 



patagium are the first, second, third and fourth interspaces. These 

 are named from the pollex toward the quintus. The series of 

 hones which is embraced in the metacarpal and phalangeal lines 

 being conspicuous in the bat, it is desirable to possess a name in refer- 

 ing to each series taken as a whole. The name digit will be used 

 for the rod of segments embracing the metacarpal element. The 

 nerve which appears at the anterior margin of a digit becomes pre- 

 digital, and that of the posterior margin, postdigital. 



The radio-metacarpal angle is the space defined by the angle of 

 union of the forearm and the metacarpus. 



The cartilaginous tip to the terminal bony phalanx respectively 

 of the third, fourth and fifth fingers will receive the name of the third 

 phalanx when three phalanges, and of the fourth phalanx when four 

 phalanges are present. 1 The shapes of the terminal phalanges are 

 of interest and some of these will be described. 



I have examined a sufficient number of genera to suggest that an 

 account of the markings of the wing-membranes, and of the shapes of 

 the terminal phalanges enter into all discriminating studies. Inas- 

 much as the account includes descriptions of these parts in the North 

 American bats the validity of the characters can be at once put to 

 the test. 



Artibeus perspicillatus. 



The prebrachium with free margin occupied with a band 1mm. 

 wide which apparently represents the tendon of the occipito-polli- 

 cal — is muscle. 



Intercostal markings conspicuous, four in number. The lowest is 

 the largest and extends as far as the ankle. The oblique band, which 

 extends upward and outward from the ankle on the mesopatagium in 

 many genera, is absent in Artibeus. The intercosto-humeral line is 

 conspicuous and extends to a point in vertical line with the elbow. 

 The vertical platysmal fascicles are about 30 in number. The 

 internal cutaneous system extends as far as end of the fifth finger. 

 It is composed of three divisions, a vertical, oblique and a horizontal. 2 



The fourth interspace is provided with a faintly marked longitu- 



1 Kolenati first identified the tips as phalanges. 



2 The horizontal line represents the main trunk of the nerve, and the verti- 

 cal and oblique lines the branches. " Inferior vertical" and "superior oblique " 

 (terms which are occasionally used in the notes) are amplifications of the last- 

 named term«. 



