PROFESSOR OWEN ON MACROPUS. 421 
The mastoid shows externally a narrow roughish vertical tract (Pl. LX XIV fig. 1, 8) 
between the exoccipital (2) and post-tympanic base of the squamosal ( 27"), which forms 
the lateral border of the occipital plane (ib. fig. 4,27), but not so broad a one as in Phas- 
colomys (Trans. Zool. Soc. vol. viii. pl. 50. figs. 2, 3, 4, 6, 7,27). The upper end of the 
mastoid has a persistent round venous aperture behind the masto-parietal fissure 
(Pl. LXXIV. fig. 1, 7). In front of that fissure is the suprazygomatic venous foramen 
(ib. fig. 1, m). 
Each parietal (ib. fig. 2, 7) extends forward in a pointed form into a corresponding 
notch of the frontal, the apex ending at the usual place of a postorbital process (ib. 
fig. 2, 12), which is rarely developed in the Kangaroos, and is never large. 
The presphenoid (ib. fig. 3, 9) extends forward to coalesce with the “septum narium;” 
its hind portion contributes to the optico-prelacerate foramen; its fore part supports 
the small orbito-sphenoid which completes that foramen, overarching it to join the 
alisphenoid, 6. 
The interfrontal suture (ib. fig. 2, 11) is persistent; even very old males of Macropus 
major show a trace of it. ach frontal begins behind, narrow or pointed, expands as it 
advances, and bends down more or less abruptly to form the inner wall of the orbit, 
where it unites with the orbito-sphenoid (10), palatine (ib. fig. 1, 202), maxillary (21x), 
and lacrymal (73); anteriorly the broad end or base of the frontal joins that of the nasal 
(15), and is wedged between the nasal (fig. 1, 15) and facial plate (21) of the maxillary. 
The frontals contribute a small share to the anterior walls of the cranial cavity; their 
chief expansion is subservient to the development of the large and complex sinuses in 
connexion with the olfactory cavity. ‘This expansion is such in Wacropus antilopinus, 
Gd., as to have suggested for it the subgeneric term Osphranter’; it is somewhat less 
developed in the present nearly allied species. 
The vomer forms the basis of the “septum narium,” and speedily coalesces with the 
plates which the prefrontals (14) contribute thereto. 
The nasals (ib. figs. 1 & 2, 15) are long and narrow; their bases, less expanded than 
in most other Marsupials, are subangular or rounded, and enter an emargination of the 
frontals between the fronto-maxillary sutures; the sides of the nasals articulate in two 
thirds of their length with the maxillaries (21), in the remainder with the premaxillaries 
(22), anterior to which the ends of the nasals are bevelled off to points, freely over- 
hanging the external bony nostril, but not extending so far forward as the dentary part 
of the premaxillary. The external nostril (ib. fig. 5) is vertically oval, narrower than 
deep; the aspect of the aperture is forward and slightly upward. 
The upper turbinal sense-capsules (ib. fig. 5, 18) coalescing with the compressed 
centrum called “‘vomer,’ and with the neurapophyses called “ prefrontals,” compose 
the bone which anthropotomy terms “ ethmoid.” 
The palatines, descending from the pre- and orbito-sphenoids, the ethmoid, and 
1 Gr. dogpavrip.os, sharp-smelling. 
