PROFESSOR OWEN ON SOME SPECIES OF THE EXTINCT GENUS NESODON. 293 
The extent of the suture of one maxillary with the opposite maxillary is 2 inches, 
and behind this the extent of the suture of the maxillary with the palatine is 
1 inch : at this part the bone gains much in depth. The palatal plate of the maxillary 
slopes from the alveolar border towards the median suture, with a curve concave 
downwards, giving an arched form to the bony roof of the mouth at its anterior two- 
thirds, behind which the bony palate is less concave transversely, and is convex 
longitudinally. The post-palatal canal opens obliquely forwards by a foramen situated 
a little in advance of the middle of the palatal plate of the maxillary a little behind 
the interval between the third {d^) and fourth {dz) teeth in the present specimen. 
The vacuity behind the maxillo-palatal plates, which was filled up by the palatines^ 
is of a nearly equilateral triangular form. 
The premaxillaries (figs. 1, 3 and 4, 22 ) are short in proportion to their height, 
are of a subquadrate form, with the part containing the mid-incisor, i 1, bent rather 
abruptly inwards to join its fellow below the nostril, the face being terminated by an 
obtuse broad muzzle. The right premaxillary is most entire ; it is a little dislocated 
outwards, and has been separated about 4 lines from its fellow, and to a less degree 
from the maxillary of its own side. The upper border, which joined the nasal (is), is 
9 lines in extent ; that which joined the maxillary { 21 ) is 1 inch 4 lines ; that which 
joined its fellow ( 22 ) is 10 lines. The palatal plate (fig. 3, 22 ) is obliquely grooved by 
the prepalatal or incisive foramina, the thin inner parietes of which have been broken 
away. 
The portion of the nasal bones preserved (figs. 1 and 2, is) show them to have been 
long and rather broad, meeting above and bent, so as to form an arch : they formed, 
with the premaxillaries, the external bony aperture of the nostrils, the maxillaries 
being excluded. 
The lower jaw (mandible, Plate XVI. fig. 6) is remarkable for the great proportion 
which the ascending ramus bears to the horizontal one. The part of the condyle pre- 
served shows it to have been transversely extended and rather convex ; the coronoid 
process rose above its level, and is separated from it by a deep emargination. The entry 
to the dental canal is 2 inches 2 lines below the condyle. From the condyle to the 
lower border of the ramus beneath the last molar tooth in place measures 4 inches ; 
from the same part of the lower border to the socket of the outer incisor is 2 inches 
9 lines, the depth of the ramus at the same part is 1 inch 4 lines. There is a faint 
linear impression along the part of the lower border which is preserved. The incisive 
part of the mandible slightly expands ; the outer surface of the horizontal ramus is, 
lengthwise, convex at its posterior two-thirds, and concave in the rest. 
The teeth preserved in the present specimen of Nesodon ovinus are, — three incisors, 
a canine, and five molars on the right side, upper jaw ; the canine and five molars on 
the left side, upper jaw; and the outer incisor, the canine and five molars in the 
right ramus of the lower jaw. 
The upper incisors, unequivocally defined by their position in the premaxillary bone, 
2 Q 2 
