14 
CROCODILES. 
clavicle; the latter being the median bar seen in the lower figure of the illustration 
on p. 10. A further peculiarity is the presence of seven or eight pairs of abdominal 
ribs in the wall of the abdomen, which have no connection with the proper ribs, 
and have their angle of union directed forwards. 1 As regards the soft parts, the 
heart differs from that of all other living Reptiles in having four complete chambers, 
so that the fresh and impure blood can only mingle by means of a communication 
between the great vessels externally to the heart; while there is also an incomplete 
midriff dividing the chest from the abdomen. 
In addition to the preceding characters, which arc common to all members of 
the order, there are certain others found only in the existing forms and some 
of their nearest extinct allies. One of the most remarkable of these peculiarities 
is the extremely backward position of the aperture of the internal nostrils, which 
in the dried skull, as shown on p. 2, is situated close up to the occiput, this being 
due to the development of special plates by the bones of the palate, which grow 
beneath the nasal passage, so as to form a floor to it, and thus completely cut it 
off from the cavity of the mouth. As the summit of the wdndpipe is continued 
upwards into this posterior aperture of the nostrils, crocodiles are enabled to 
breathe while their mouths are wide open and filled with water. Another dis¬ 
tinctive feature of the group, also shown in the figure just referred to, is that the 
socket for the eye communicates freely behind with the lower temporal fossa. 
Then, again, all existing members of the order are characterised by the bodies of 
the vertebrae having the ball behind and the cup in front; while the ribs of the 
chest are provided with liook-like or uncinate processes resembling those of birds. 
In the region of the neck the ribs present the peculiarity of having backwardly 
projecting and overlapping processes, which effectually prevent these animals from 
turning their heads to one side. 
Crocodiles are denizens of the tropical and subtropical regions of 
Habits x i o 
the globe, and are found in such latitudes wherever there are rivers 
or fresh-water lakes of sufficient size for their mode of life; while one of the 
Indian species habitually resorts to the sea-coast, where it has been seen floating at 
a considerable distance from the land. All of them are excellent swimmers, and 
are mainly propelled when in the w T ater by the aid of their powerful tails; the 
limbs being chiefly used when walking at the bottom of the water, or on the shore. 
When in repose, crocodiles lie like logs either in the water or on the banks of the 
lakes or rivers they inhabit; but when in pursuit of their prey in the water they 
move with great speed, while they are also active on land. The young are, 
however, decidedly nimbler in their movements than are the adults. Exclusively 
carnivorous in the diet, some members of the order feed solely upon fish; while 
others, in addition to fish, prey upon the flesh of all animals that come in their 
way. Adult crocodiles, writes Dr. Gunther, “ attack every large animal which 
accidentally approaches them, and in overpowering it the whole of their powerful 
organisation is called into requisition. Seizing the victim between their capacious 
jaws, and fastening their long, pointed, conical teeth into its flesh, they draw it, 
in one moment, by their weight and with a stroke of the tail, below the water and 
drown it. Their gullet is, however, much too narrow to allow of the passage of 
1 These abdominal ribs, connected together by the ligament, are shown in the figure above referred to. 
