422 PROFESSOR OWEN ON MACROPUS. 
frontal (at 202, fig. 1), internal to the hind part and entorbital plate of the maxillaries 
(21), bend inwards at right angles to unite together at the bony palate (ib. fig. 3, 20), of 
which they form the hind portion from the penultimate molars backwards. From the 
sockets of these and of the last molars the palatal plates of the palatines are separated 
by a narrow strip of the maxillaries (ib. 21”), behind which the palatines (20") extend 
and expand to join the pterygoids (24). 
The hind border of the bony palate is feebly concave. The postpalatal apertures 
pierce the outer angles of the palato-maxillary sutures; they are small oval foramina in 
some (usually the larger) species of Kangaroo (as at 0, fig. 3), but extend into both 
bones to form wide vacuities in other species’, the bony palate being one of the seats of 
variety in the present family. The proper palatine plates may show one or more fora- 
mina behind the normal postpalatal or maxillo-palatine vacuities. 
The orbital plate (ib. fig. 1, 207) of the palatine is pierced by the orbito-palatal 
foramen, and is notched to contribute, behind, to the spheno-palatal foramen, and, in 
front, to the palato-maxillary foramen. 
The maxillary is a large and complex bone. Articulating with the fore and outer 
parts of the palatine, it develops the alveolar tract for the grinders, also the part of 
the bony palate between the palatines and premaxillaries, and the main part of the 
floor of the orbits, where it is pierced by the entorbital canal (¢) and notched by the palato- 
maxillary foramen (f'). Then, these extending from the orbit forward, beneath, or 
internal to the lacrymal and malar bones, the maxillary forms the side wall of the face 
(fig. 1, 21) as far forward as the premaxillary (ib. 22). This facial wall of the maxillary 
is sinuous, convex vertically at its upper part, concave at its lower part, the concavity 
being deeper in the larger kinds of Kangaroo: it articulates behind with the frontal 
(11), lacrymal (73), and malar (26), above with the nasal (15), in front with the premaxillary 
(22). At the lower part of the maxillo-premaxillary suture the maxillary usually sends 
forward a sharp narrow process to be wedged into the premaxillary, receiving into a 
notch below a similar process from that bone. The suborbital canal divides into a dental 
and an antorbital canal. The anterior outlet (ib. fig. 1, 21’) of the antorbital canal, 
usually vertically oval in shape, varies in its relative positions to the orbit in different 
species of Kangaroo. A ridge near the maxillo-malar suture leads to the zygomatic pro- 
cess, of which it forms the outer border. This process (21x) is the seat of variety, as 
to shape and size, in different species of Macropodide. 
The premaxillaries unite by a rhomboid facial plate (ib. fig. 1, 22) with, usually, the 
terminal third of the nasals (15) and with the maxillaries (21). They develop sockets 
for three pairs of incisors (é 1, 2, 3), and form the anterior end of the bony palate, which 
is pierced by the “incisive foramina” (ib. fig. 3, 22’) in the form of oblong slits, closed 
behind by the pointed ends of the palatal plates of the maxillaries. External to these 
foramina the premaxillaries usually show a smaller foramen (ib. a’). 
* Trans. Zool. Soc. vol. ii. pl. 71. fig. 5 (Halmaturus bennettii). 
