no 
BUCK-BILLED PLATYPUS. 
way along the beak. The beak itself is covered 
with a smooth black skin, that extends some way 
beyond the bones, both in front and laterally ; and 
forms a moveable lip,, so strong, that when dried 
or hardened in spirit, it seems to be quite rigid ; 
but when moistened is very pliant, and is probably 
a muscular structure. The under portion of the 
beak ha3 a lip equally broad with the upper. 
This has a serrated edge (wanting in the upper 
mandible), but the serr?e are mostly confined to 
the ^oft part. A curious transverse fold of the 
external black smooth skin, by which the beak is 
covered, projects all round, exactly at that part 
where it has its origin. The apparent use of this 
is to prevent the beak from being pushed too fkr 
into the soft mud, in which prey may be concealed. 
The nerves that supply the beak, are much allied 
to those of birds ; and the cavity of the skull has a 
greater resemblance to that of a duck than of a 
quadruped. The eye is uncommonly small for 
the 9ize of the animal ; and the external opening of 
the ear is simply an orifice, and so minute as not to 
be discovered without difficulty. 
From the form of this animal, we are led to sup- 
pose it a resident in watery situations ; that it bur- 
rows in the banks of river9, or under ground, and 
that its food consists of aquatic plants and animals. 
But the structure of its beak is guch as not to en- 
able it to lay firm hold of its prey : when, how- 
ever, the two marginal lips are brought together, 
the animal has most probably a considerable power 
of suction, and in this manner may draw food into 
its mouth. 
