264 ON PLATYGONUS COMPRESSUS : 



fig. 2, base view ; fig. 5, A, top view. From it we learn that the 

 head was very narrow, and compressed on the sides ; the canines 

 were concealed by the lips, and projected forwards downwards, and 

 a little outwards. The malar plate of the superior maxilla is ex- 

 panded very obliquely outwards, and above it is a wide but shallow 

 groove (a, a, fig. 1), which is parallel with the superior suture, and 

 vanishes opposite the first premolar. 



Above the superior canine, the bone swells out into a somewhat 

 acute prominence, from which a concavity (/, A, fig. 5), expand- 

 ing as it advances, looking outwards and a little forwards, runs 

 towards the incisor. The suture of the intermaxillary bone passes 

 upwards and backwards very close to the canine, and almost in 

 contact with the anterior wall of its socket. 



The ossa nasi are very convex from side to side, forming a semi- 

 circular arch ; they are also very slightly arched antero-postcriorly. 

 About the region of the canines, the skull expands a little, the lat- 

 eral surfaces being there flattened and oblique. From a small frag- 

 ment (fig. 3), containing the root of the first premolar, it will be 

 seen that an elevated line originates opposite that tooth, and is lost 

 before reaching the canine ; this line is parallel to the alveolar mar- 

 gin j immediately above it, and a little anterior to the first premolar, 

 is a small foramen (a, fig. 3). Below the elevated line is a deep 

 longitudinal concavity, oblique downwards, separated from the pala- 

 tal plate by a second elevated line. The palatal plate is seen in 

 fig. 2 ; it is concave transversely, with flattened sides ; by pick- 

 ing away the cement at the anterior part of the fragment, it ap- 

 peared that this concavity becomes more narrow anteriorly, at the 

 same time increasing in depth, until it assumes the form of a medial 

 groove. On each side are the remains of a deep groove (a, a, 

 fig. 2) ; and by reference to the palatal part of the small fragment 



