NYCTEEID.E AND MEGADERMATID.E. 
103 
Families NYCTERID.13 and MEGADERMATID^. 
In the Nycteridse the nostrils are very small, and are situated on each side of a deep 
hairless depression on the upper surface of the snout, the point of which slopes 
downwards and forwards, and is covered with short hairs and a few long fine hairs. 
The mesial line of the posterior margin, overlooking the pit in which the nostrils lie, 
has a somewhat backwardly projected process. The nasal pit is the anterior ending 
of a well-defined deep mesial longitudinal facial furrow, which is divided into two parts. 
The first part, from the nostrils backwards to about level with the eyes, is not 
so deep as the section immediately behind it. The latter begins anterior to a 
transverse line connecting the two small eyes. This hinder portion has its floor at 
a lower level than the anterior portion. The margins of this great and deep facial 
furrow are defined externally on each side by three folds of skin. The first is a more 
or less pedunculated lobe immediately behind the line of the nostrils; its inner surface 
is perfectly round, flat, and hairless, and is generally opposed to its fellow of the 
opposite side, so that the openings to the nostrils are reduced to two oblique slits 
defined posteriorly by these lobes, and anteriorly by the nasal margin of the snout, 
which has usually a more or less defined backwardly projected eminence. Ttie upper 
surface of each of these lobes is well covered with hair. Internally to this, and in the 
bottom of this part of the furrow, there is a hairless fold of skin arising on the inner 
side of each nasal orifice and curving backwards and outwards, and terminating on the 
upper edge of the facial furrow, on a line, or nearly so, with the beginning of the 
portion of the facial furrow lying at a deeper level. A small lobe on the commencement 
of each of these folds exists opposite to each nostril, and, having a gentle outward 
curvature, is opposed to the outer wall of the furrow immediately over the nostril. 
The posterior part of the outer wall of this fold is clothed more or less with hairs. 
The second portion of the facial furrow is traversed by a median fleshy septum, attached 
posteriorly to the front of the frontal bone. Each outer wall of this part of the facial 
furrow' curves outwards and backwards, and ends in a free fleshy process that lies 
opposed to the upper surface of the lateral offshoots of this part of the facial ridge 
externally to the termination of the foregoing septum. On each side of the septum 
there is a semicircular pit with a delicate membrane covering its floor. The posterior 
ending of the septum is practically in the mesial line of the membrane connecting the 
ears. 
The nose-leaf of the Megadermatidse is structurally widely distinct from that of the 
Nycteridse. It attains to a great size, is composed of two portions, the smaller 
connected with but overlying the larger portion. The latter begins on the upper 
surface of the snout as a procumbent fold of skin with a more or less free border, and 
