CARNIVORA. 775 
strong and sharp; some of the back teeth are generally 
sharp, and specially adapted for cutting. 
There are generally strong occipital and sagittal crests for 
the insertion of muscles of neck and jaw. The glenoid 
fossa for the articulation of the lower jaw is deeply concave, 
and bounded by a large postglenoid process, the result 
being that the lower jaw can only move up and down. 
This is important, as it minimises the risk of any failure 
of grip in seizing living prey. The muscles of the lower 
jaw are very strongly developed, and with this may be 
associated the strength and the protrusion of the zygomatic 
arch in the more specialised types. The widening of this 
arch has prevented the formation of a frontal bridge behind 
the orbit, so that the orbit is confluent with the temporal 
fossa. There is a strongly developed and ossified tentorium 
descending between cerebrum and cerebellum. The tym- 
panic bullee are in most cases large. 
The clavicles are incomplete or absent (an important 
contrast with all Insectivora except Potamogale) ; the radius. 
and ulna are always distinct; the fibula is slender but dis- 
tinct. The scaphoid and lunar bones are fused. 
The cerebrum is well convoluted, and the cerebellum is. 
more or less covered by the cerebrum. 
The stomach is always simple; the czecum is absent, or 
short, or simple ; the colon is not sacculated. 
There are no vesicule seminales. The uterus is bicor- 
nuate) The mamme are abdominal. The placenta is 
deciduate and zonary. 
‘ Representatives of Carnivora are found in all parts of the 
world. 
The true Carnivores are for the most part terrestrial. The incisors 
are almost always 3, the canines are usually large; one of the 
back teeth is modified as a trenchant carnassial or sectorial. 
The digits generally have sharp claws, which may be retractile. 
Within the sub-order there are three sections—®luroidea, 
Cynoidea, and Arctoidea—represented respectively by cat, 
dog, and bear, but these types are connected by extinct 
forms. : 
In retractile claws, the last phalanx of the digit with its attached 
claw is drawn back into a sheath on the outer side of the middle 
phalanx in the fore-foot, on the upper side in the hind-foot. When 
the animal is at rest or is walking, the claw is retained in this bent 
