504 On new Species of Nyctinomus. 
This bat differs from all known members of the genus by 
its possession of the unique caudal gland above described. 
In other respects it is a true Nyctinomus, belonging to the 
typical group with imperfect premaxille. 
Nyctinomus demonstrator, sp. 0. 
A medium-sized thick-set species with united premaxille, 
conjoined ears, and small scent-glands on each side of the 
penis. 
Ears rather small, rounded, united at their inner bases for 
a height of about 2°5 millim., but without any folded lobe: 
keel slightly thickened in lower third; antitragus higher 
than long. rounded above, with a broad base ; tragus minute, 
broader above than below, with an incurved upper angle and 
concave anterior margin. Lips wrinkled. No gular sac. 
Pad at base of thumb rather small. Wings to the distal 
third of the tibia. ‘Tail involved in membrane for about half 
its length. Penis unusually short, or at least appearing 
short, as it projects by its tip only from the swollen mass of 
a pair of scent-glands surrounding its base, their two openings 
separated by a narrow septum situated halfway along the 
penis on its lower surface. 
Fur very short and close, that on the forehead behind the 
junction of the ears appearing to be suffused with some oily 
secretion. 
Colour dark brown above, more blackish on head ; below 
also brown, the median area more greyish brown. Wing- 
membranes brown above and below ; interfemoral membrane 
brown above, whitish below. 
Skull low, stont and strong; brain-case small; muzzle 
narrow. Median crest not developed except in the interorbital 
region ; premaxille united round the small palatine foramina. 
Upper incisors long, straight, almost parallel, not far apart ; 
lower incisors four, bilobate, the outer pair rather smaller 
than the inner; anterior upper premolar present, but ex- 
ceedingly minute, placed in the outer angle between the 
canine and large premolar, which touch one another. 
Dimensions of the type (measured in spirit) :— 
Forearm 44 millim. 
Head and body 64 ; tail 832; ear 17; tragus 2:0; height 
of antitragus 3 ; third finger, metacarpus 43, first phalanx 18, 
second phalanx 18; fifth finger, metacarpus 27, first phalanx 
12-4, second phalanx 5; lower leg and foot (s. u.) 22. 
Skull: greatest length 19°7: basal length in middle line 
15°8; zygomatic breadth 12:7; anteorbital breadth 7; con- 
