314 PROCEEDINGS OF THE ACADEMY OF [1889. 



position time is saved and the animal preserved intact. As may- 

 be anticipated the value of these characters varies in different 

 groups. But even when they are not sufficiently trenchant to serve 

 for the identification of species or genera, they always indicate 

 affinities, and enable the observer, independently of other aids, to 

 narrow the surmises of recognition to a limited field. 



The details are of restricted use in studies of the dried skins. 

 All statements (with three exceptions) must be considered as applica- 

 ble to alcoholics only. 



I have found it convenient to employ a number of names for the 

 subdivision of the dermal expanse. Those which are now used for 

 the first time are italicized. 



The membrane which extends from the sides of the trunk to 

 include the anterior extremity is the wing membrane (" bat-wing," 

 patagium). 



The membrane between the legs is the interfemoral membrane 

 (uropatagium). 



The wing-membrane above the arm and forearm is the 'pre-, 

 brachium (antebrachial membrane, propatagium). 



The wing-membrane below the arm and forearm would become 

 antithetically the postbrachium. But since the postbrachium 

 could not be separated from the sides of the trunk and the legs it 

 has been found necessary to discard it. 



The part of the wing-membrane lying between the body, the 

 humerus, the lower extremity and a hypothetical line drawn down- 

 ward from the elbow and intersecting the free margin of the mem- 

 brane, is the endopatagium. (PI. X, fig. 1.) 



The boundary at the elbow is often fixed by the vertical terminal 

 branch of the intercosto-humeral line. The subordinate lines (prob- 

 ably platysmal in origin) in the endopatagium incline obliquely 

 either toward the humerus or the trunk. 



The part of the wing-membrane which is limited by the line at the 

 elbow as above given, by the forearm, and the fifth metacarpal bone 

 and phalanges, is the mesopatagmm* Within the mesopatagium the 

 subordinate lines incline either toward the forearm or the manus. 



The part of the wing-membrane limited to the manus becomes the 

 ectopatagium (dactylo-patagium). The subdivisions of the ecto- 



* The endopatagium and mesopatagium are together the same as plagio- 

 patagium of Kolenati. (Beitr. z. Naturgesch. der Europ. Chir. Dresden, 1857.) 



