220 
PKOFESSOR H. G. SEELEY OX THE STRUCTURE, ORGANIZATION, 
the condition in many Marsupials. The exposed temporal foss is said to give a Carni¬ 
vorous Mammalian character to the skull. 
On the right side of the type-specimen of D. leoniceps (Owen), British Museum, 
No. 47,047, the base of the columella is exposed, rising from the posterior part of the 
pterygoid bone. It has a comparatively long basal attachment, and extends obliquely 
upward and forward. It is imperfectly indicated in ‘ Cat. South African Reptiles,’ 
PJate XXIV., above the number 24, but is not described. 
The specimen figured in this plate seems to me to give no support to the interpre¬ 
tation of the palate there given. The separation between what are interpreted as the 
pterygoid and palatine bones, as shown in the figure, has no existence. The bone is 
divided on one side but not on the other ; and the division is probably due to fracture. 
If the anterior portion were really separate, it would be the transverse bone, and not the 
palatine ; but no such division in the pterygoid is to be detected in any of the numerous 
specimens which display that bone. Hence, the pterygoids are commonly united 
below the sphenoid, in the median line (though apparently separate in No. 47,056), 
and they are constricted from side to side at their confluence. They send a process 
on each side backvvard and outward to the quadrate, and forward and slightly outward 
to the maxillary. The latter union takes place below the orbit, and excludes the 
palatine bone from the external border of the palatal arch. The palatine bone may be 
found on each side, in close squamous contact with the anterior bar of the pterygoid, 
along its inner side. It extends backward to the point where the inner diverging 
fork or plate of the pterygoid is given oft’ (Brit. Mus., No. 47,047 ; and ‘ South African 
Catalogue,’ Plate XXVI., fig. 1). Anteriorly the bone widens, and externally is wedged 
between the pterygoid and maxillary bones, and internally processes from the two 
sides converge forward to meet the vomer, which divides them, but is not drawn in 
Plate XXVI., fig. 1. If the median inter-palatine space had been excavated deeper, it 
is probable that the internal pterygoid processes between which the number 24 is placed 
on Plate XXVI. would have converged forward to form a median vertical pterygoid 
plate, which would have extended forward to meet the vomer, this being the usual 
relation of the bones in other specimens. 
No other specimen which has been described shows so perfectly the form, size, 
and relations of the quadrate bone, though its individuality has been ignored in 
Plate XXIV., where only a broken mass of bone is indicated above the condyle, 28. 
The median descending broken mass, with a black anterior outline in the figure, is 
part of the squamosal, extending laterally downward over the quadrate bone. The 
dark oval space in the figure a little behind this bone, and 7 or 8 centims. above 
the condyle, is part of the proximal surface of the quadrate bone, laid bare by a piece 
of the squamosal bone being broken away from behind it, so that the bone is received 
into an arch in the squamosal, and its entire ai^terior extent is exposed looking 
obliquely forward and outward. The extreme height of the bone on its external 
border against the squamosal is 10 centims. from the base of the condyle. At that 
