GENE KALNCHARACPERTISTICS. 351 
shaped hollow—the glenoid cavity—in the skull, bounded by overhanging edges. 
In consequence of this arrangement, the motion of the lower jaw of a Carnivore is 
strictly limited to an up-and-down direction; thus allowing only of a biting or 
snapping action, and not permitting that rotatory or backwards-and-forwards 
movement found in so many other Mammals. The interlocking of the lower jaw 
with the skull is most marked in the badgers. ‘ 
A less important feature of the carnivorous skull is to be found in the cireum- 
stance that in the great majority of instances the orbit, or the cavity for the eye, is 
not bounded posteriorly by a bar of bone so as to form a complete ring, but com- 
municates freely with the greatly elongated hollow on the side of the skull which 
contains the powerful muscles for working the jaws. Occasionally, however, as in 
some cats and the ichneumons, the eye-socket is completely surrounded by a bony 
ring; and a process at the back of the upper part of the cavity for the eye always 
marks the posterior limit of that cavity. More constant is the presence of a 
strong zygomatic arch bounding the inferior border of the socket of the eye, and 
connecting the upper jaw with the region of the ear. 
An important feature distinguishing the skeleton of a Carnivore from that of 
an Insectivore (with the exception of the potamogale) is that the collar-bones or 
clavicles are frequently absent, and when present are never complete; that is to 
say, that instead of each collar-bone forming a bar to connect the shoulder-blade 
with the breast-bone, as in ourselves, when it exists at all it merely forms a little 
splint of bone embedded in the muscles of the chest between these two points. 
Two other features in regard to the skeleton must not be overlooked, since 
they are of some help in distinguishing between Carnivores and Insectivores. In 
many of the latter, as shown in the figure of the skeleton on p. 332, the two bones 
of the fore-arm (radius and ulna), and of the lower leg (tibia and fibula) are 
respectively united together, whereas in all the former they are completely 
separate. In the fore-limb this separation of the two bones is essential in order to 
permit of the free use of the paw. A characteristic of the wrist-joint of all 
Carnivores is that two of the bones of the upper row, respectively known as 
the scaphoid and the lunar, are completely welded together; and it may be added 
that the central bone, which we have seen exists in all the lower Primates, is 
invariably absent. Another feature distinguishing the Carnivores from the 
Insectivores is to be found in the well-marked convolutions on the upper surface 
of the lobes of the brain, which is indicative of a far higher degree of mental 
power. 
With the exception of Australia and New Zealand, Carnivores are distributed 
over all the continents and larger islands of the globe, ranging from the icy ocean 
of the Arctic circle to the tropical plains of Africa and India; but while some 
of the families, like the cats and dogs, have a distribution almost coextensive 
with that of the order, others, like the civets and hyenas, are much more 
restricted in their range. Exclusive of the larger Man-like Apes, the Carnivores 
include the largest of the so-called Unguiculate Mammals, that is, those in which 
the toes are furnished with claws or nails, in contradistinction to hoofs. As is 
usually the case, the largest representatives of the order are to be found in the 
aquatic section, where we have the walrus and elephant-seal. Among the terres- 
