102 
MR. W. K. PARKER ON THE STRUCTURE AND 
it is separated from the palatine process by a deepish concavity; the two processes 
reach backwards about the same extent. The re-entering angle between the two 
processes is rounded for the opening of Jacobson’s organ (see also fig. 5, j.o.), and the 
wedge-like end of the maxillary (mx.) reaches up to this passage. 
The maxillaries are nearly half as long as the whole basal line, from the fore end of 
the snout to the foramen magnum, and their alveolar tract is really large, behind, 
where the two last teeth, with their subdivided pulps, take on somewhat of a 
Zeuglodontic character. 
The first of the simpler front teeth—there are five, in all, at this stage—would 
answer to the second or third premolar, of a Hedgehog or a Mole; all those that 
should be in front of this part are suppressed, and yet the jaw-bones have suffered but 
little by this suppression. 
The palatine plates of the maxillaries certainly do resemble those of the Armadillos 
(see Plate 2, fig. 2), for inside the steep alveolar wall the great palatine flange, at first 
scooped, rises into a ridge, and is then separated by another concave and grooved tract 
from the lesser submesial tract of bone. This tract is deficient, both before and 
behind ; in front it lets us see the fore part of the main vomer (v.) and the small 
front paired vomers (y', see also fig. 5). The main part of the maxillaries ends a little 
in front of the palatine end (pa. ) of the hard palate, but at present the last alveolus 
is not walled in. The shoulder of the maxillary, its jugal region, extends outwards 
nearly as far as any part of the skull, the only wider part is the glenoid region ( gif ). 
The infraorbital canal (V 3 .) is one-fourth the length of the maxillary, and its opening- 
in front is infero-lateral. 
The total length of the palatines (pa. ) is half that of the maxillaries, but they 
form less than one-third of the hard palate ; that tract runs in between that of the 
maxillaries, leaving those bones only a narrow flange, there, inside the inner alveolar 
wall. The two plates do not meet well together, especially in front, and each forms, 
in this part, a rounded leafy plate of bone, fitting against a large, rounded notch on 
the inner angle of each maxillary plate. 
The margin of each palatine, behind, is rounded, and has a strong rim, which is 
distinct from the thickened outer rim of the bone at its articulation with the end of 
the maxillary. Under that outer rim, which forms a bridge, there is a large oblique 
oval passage, or subway, and from it, in front, a groove runs forwards, along the outer 
third of the flat plate. The unfloored part of each palatine is only two-thirds as long 
as that which helps to form the hard palate; it is thick-edged below, and that edge 
does not project so far out-wards as the hinder rim of the completer part; above, it is 
oblique, with a shortened upper margin, to which there is scarcely any basicranial 
flange. , 
The pterygoids (behind pa.) continue the wall to the nasopalatine canal, they are as 
long as the palatines, and have a broader basicranial flange, which runs backwards, and 
is emarginate in front of the Eustachean opening (eu.). The short thick hamular 
