With the bandicoots, or _Peramelidae_, we come to a family of
polyprotodonts which resemble the diprotodonts in the peculiarly
specialized structure of their hind limbs; an adaptation which we must
apparently regard as having been independently acquired in the two
groups. The dentition is i. 5/3, c. 1/1, p. 4/4, m. 3/3; total, 48;
the upper incisors being small, with short, broad crowns; the lower
incisors moderate, narrow, proclivous; canines well developed.
Premolars compressed, pointed; and the molars with quadrate
tuberculated crowns. Deciduous premolar preceded by a minute
molariform tooth, which remains in place until the animal is nearly
full grown. Fore feet with two or three of the middle toes of nearly
equal size, and provided with strong, sharp, slightly curved claws,
the other toes rudimentary. Hind feet long and narrow; the first toe
rudimentary or absent; the second and third very slender and united in
a common integument; the fourth very large, with a stout elongated
conical claw; the fifth smaller than the fourth (see fig. 6). The
terminal phalanges of the large toes of both feet cleft at their
extremities. Head elongated, with the muzzle long, narrow and pointed.
Stomach simple. Caecum of moderate size. Pouch complete, generally
opening backwards. Alone among marsupials bandicoots have no
clavicles. More remarkable still is the development of a small
allantoic placenta.
[Illustration: From Gould.