COLLECTION OF BATS. 283 
concave — smooth in rufus —, the glandular elevations 
on the sides much more developed than in rufus. Lower 
lip projecting and grooved like in rufus. A not described 
characteristic present in both species is a well developed 
fold of the skin connecting the ear to the upper part of 
the head. Ears still shorter than in rufus, a little higher 
than the crown of the head; the outer margin of the ear 
terminates in a larger and much more rounded off wart 
than in rufus; tragus less hairy on its front surface and 
the outer margin not toothed like in rufus, 
Thumb shorter than the foot; a large cushion at the 
base of the metacarpal bone, the second cushion so well 
developed in rufus, is absent in Youngii. Interfemoral mem- 
brane from about the heels: heel without projecting cushion: 
feet stronger and broader than in rufus, for the rest like 
in that species, 
Much lighter colored than rufus: the wingmembrane 
between second and third finger for its greatest part white 
colored: the wingmembrane between third and fourth finger 
white colored from about half way the second phalanx 
downward, a white triangle on the wing-membrane between 
the second phalanges of the fourth and fifth fingers. 
The dentition seems not to differ from that of rufus. 
I make it me a great pleasure to connect this very in- 
teresting new species, the second well established of the 
genus Desmodus, with the name of a man, to whom our 
Museum is indebted for so many additions to its collec- 
tions of the British Guyana animals, 
Notes from the Leyden Museum, Vol. XV. 
