ESPECIALLY MYCTOPHOIDS 47 
The ectopterygoid is bent through a slight angle towards its posterior end where it 
slopes postero-ventrally to meet the quadrate. Anteriorly the ectopterygoid con- 
tacts the postero-ventral region of the palatine and there is a slight angle between the 
two bones, the palatine not forming a direct continuation of the ectopterygoid. The 
ectopterygoid bears a single row of teeth ventrally which are not regularly placed. 
The teeth are firmly fused to the bones and have large expanded bases which are 
practically circular in cross-section. The teeth themselves become laterally com- 
pressed apically to give rise to anterior and posterior cutting edges. The posterior 
cutting edge is further increased by the production of a post-apical barb. The teeth 
decrease in size posteriorly. The internal edge of the bone is inclined dorso-medially 
where it contacts the endopterygoid. 
The endopterygoid is a thin sheet of bone lying in a horizontal plane and its in- 
ternal edge is associated with the lateral edge of the parasphenoid forming the roof of 
the mouth. Dorsally the endopterygoid is concave where it lies below the orbit. 
The convex ventral surface is covered by a large, roughly oval patch of minute teeth. 
Posteriorly the endopterygoid lies medial to the anteriormost extension of the meta- 
pterygoid. 
The metapterygoid is a thin laminate bone superficially placed so as to cover the 
posterior extent of the endopterygoid and the anterior expansion of the hyomandibu- 
lar. Posteriorly the metapterygoid is irregularly rounded but anteriorly there is an 
oblique ridge forming the upper part of the anterior border; the lower part of the 
anterior border expands slightly in front of this oblique strengthening ridge. 
Ventrally the metapterygoid meets the ectopterygoid and the dorsal edge of the 
quadrate. 
The palatine is large and elongated. The ectopterygoid attaches to its ventral 
surface near the posterior end, which is expanded towards the mid-line, irregularly 
ridged dorsally and was in life filled by cartilage, providing the articulatory facet for 
the ventral region of the lateral ethmoid. The palatine has a convex dorsal surface, 
but the ventral surface is concave so that an elongated ventral groove is present 
longitudinally. Anteriorly the palatine tapers to a point and ends on a level with 
the anterior mesethmoid region. Along the medial face of the palatine two longi- 
tudinal grooves are present, a dorso-medial groove along the anterior half of the bone 
with which the lateral edge of the mesethmoid articulated, and a ventro-medial 
groove extending practically the whole length of the bone into which the lateral edge 
of the expanded vomer fits. On the lateral face of the palatine near to the posterior 
end there is a shallow obliquely orientated groove which houses the anterior end of 
the maxilla. In the ventral longitudinal groove of the palatine two major tooth 
rows are found (Woodward, 1902 : 45, fig. 10). The inner row is the more im- 
portant and is a direct continuation of the row of ectopterygoid teeth. Anteriorly 
the bone narrows and the teeth are reduced to a single row. At the posterior end of 
the palatine the teeth become much enlarged and the bone ends with one enormous 
tooth of the inner row. The teeth are identical to those on the ectopterygoid except 
that the outer teeth are not provided with a post-apical barb. The inner row of 
teeth is represented by 11 tooth sockets or teeth and the teeth in the middle of the 
