6 Watson, The larger Coal Measure AvipJiibia. 



of the skull, whose lower tooth-bearing border alone 

 appears on the palate, lying along the thickened edges of 

 the pre-vomer, palatine, and transverse bones ; it forms a 

 portion of the outer side of the internal nasal opening. 

 It is a curious fact that in Loxovima the palatine is fused 

 with the lachrymal, although both bones are quite free 

 from the easily detached maxilla. 



Pteroplax is best represented by the skull which was 

 described b\' Atthev as '■'Anthracosauriis RiisselUr His 



Fig. 2. Skull of Pteropla.x sp. I'alatal aspect. 

 Reference letters as on Fig. i. 



description of the upper surface is quite accurate, except 

 that he treats part of the pterygoid as the quadrate, and 

 taken in connection with his excellent figures gives a good 

 idea of the general form of the skull. 



I have never seen a Basi-occipital, but it must have 

 been very similar to that of " Loxonnna,'' except in 

 appearing in the lower border of the foramen magnum. 



