ESPECIALLY MYCTOPHOIDS 133 
The symplectic is small and inclined forwards ventrally. Dorsally it is separated 
from the hyomandibular and ventrally lies in a groove on the posterior part of the 
medial face of the quadrate. 
The quadrate is a large triangular bone with a transversely orientated condyle at 
its ventral angle. The groove which housed the symplectic is long and shallow and 
ends just behind the condyle. The postero-dorsal corner of the quadrate is emargi- 
nated. The posterior edge however is thickened and slightly grooved to house the 
leading edge of the preoperculum. Dorsally the quadrate meets the metapterygoid 
and anteriorly the ectopterygoid. 
hm.h 
OR op.p.hm 
aoe Ho hm VII 
Fic. 60. Halec eupterygius (Dixon). Hyopalatine and opercular bones and mandible 
of the left side, medial view. 
The metapterygoid is large, thin and membranous. On its lateral face it has a 
crest which originates antero-ventrally and passes postero-dorsally. More dorsally 
this crest marks the anterior edge of the metapterygoid. 
The ectopterygoid is bent through a slight angle posteriorly where it extends 
below the anterior part of the quadrate. The anterior end of the ectopterygoid 
abuts against the palatine and the dorsal edge contacts the endopterygoid. Teeth 
are present on the ectopterygoid and are of two types. The first are prominent 
marginal teeth which decrease in size posteriorly where they also become closely 
crowded. These teeth are acutely pointed, recurved and with a slight lateral 
