408 PROF. OWEN ON THE OSTEOLOGY OF THE MARSUPIALIA. 
power of the foot is concentrated in all these genera on the two outer toes, but especially 
the fourth, which in the Great Kangaroo is upwards of a foot in length, including the 
metatarsal bone and the claw, which latter resembles an elongated hoof, but is three- 
sided and sharp-pointed, like a bayonet. It is with this formidable weapon that the 
Kangaroo stabs and rips open the abdomen of its assailant ; it will hold a powerful dog 
firmly during the contest with the anterior extremities, and firmly supporting itself be- 
hind upon its powerful tail, deliver its thrusts with the whole force of the hinder ex- 
tremities. 
The cuboid bone, which supports the two outer metatarsals in the Poephaga, is pro- 
portionally developed. The internal cuneiform bone is present, though the toe which 
is usually articulated to it is wanting ; it is also the largest of the three, and assists in 
supporting the second metatarsal ; it is joined with the naviculare and external cunei- 
form, the small middle cuneiform occupying the space between the external and in- 
ternal wedge-bones and the proximal extremities of the two abortive metatarsals. The 
great or fourth metatarsal is straight, and somewhat flattened ; the external one is com- 
pressed and slightly bent outwards ; the toe which this supports is armed with a claw 
similar to the large one, but the unguial phalanx does not reach to the end of the 
second phalanx of the fourth toe, and the whole digit is proportionally weaker. 
PLATE LXVIII. 
Side-view of the skeleton of the Wombat (Phascolomys Wombat). 
PLATE LXIX. 
Views of skull and lower jaw of the Koala (Phascolarctos fuscus). 
PLATE LXX. 
Fig. 1. Base of the skull of the Thylacinus Harrisii. 
2. Base of skull of Dasyurus viverrimus. 
3. —————— Dasyurus Maugew. 
4. Dasyurus macrourus. 
D. —— Dasyurus Ursinus. 
PLATE LXXI. 
Fig. 1. Base of the skull of Perameles lagotis. Fig. 6. Base of the skull of Phasco- 
2; ———— Phalangista Cookit. lomys Wombat. 
3. ———_—_—____ Petaurus breviceps. 6 a. Exoccipital bone. 
4. —— —— Hypsiprymnus Hun- 6 b. Tympanic bone. 
tert. 6 c. Pterygoid bone. 
a: ——— Macropus Bennettii. 6 d. Inferior maxillary bone. 
