198 OBSERVATIONS ON THE ANATOMY OF 
The roof of the palate is covered with a black cuticle, 
and is marked with about fourteen elevated transverse 
ridges, slightly curved forwards, and formed by folds of 
the membrane lining the mouth. The roughness produced 
by these elevated ridges must greatly assist the tongue in 
retaining small moving objects, like insects, endeavouring 
to escape from the mouth, and in extracting the soft nutri- 
tious parts from their horny coverings; and it will be 
shewn hereafter that this is the kind of food on which the 
Perameles subsists. These folds are likewise found in the 
Opossum, but in smaller number. The fauces were nar- 
row ; the epiglottis broad and short, as in the Opossum, 
but with a groove on its free margin, corresponding with 
the posterior end of the rima of the glottis; the cartilagi- 
nous rings of the trachea were very soft and thin, and 
formed complete circles, divided only by a fissure on their 
posterior side ; in this respect the trachea has some resem- 
blance to that of birds, where the rings are generally com- 
plete. The right lung was rather larger than the left, 
from the heart lying a little to the left side ; it was divided 
by two deep transverse fissures into three lobes, the supe- 
rior of which was the smallest, and its form was adapted 
to that of the upper narrow part of the thorax ; the middle 
division of the right lung formed a long, curved, tapering 
lobe, extending horizontally forward under the apex of the 
heart, which, in this animal, is placed rather high in the 
thorax. The inferior lobe was as large as both the pre- 
ceding, of a triangular form, with its apex pointed down- 
wards. There was likewise a small divided appendix to 
this lung, placed on the right side of the mediastinum, and 
lying behind the apex of the heart. The left lung consist- 
ed of one undivided lobe, the dorsal margin of which is 
broad and round ; this lung tapers gradually to its sternal 
margin, which is very thin and semicircular. Daubenton 
