ESPECIALLY MYCTOPHOIDS 207 
canal also transmitted the preopercular sensory canal. Laterally the pterotic is 
deeply excavated as the dilatator fossa. The anterior part of this fossa is however 
formed from a postero-dorsal excavation of the sphenotic, and the suture between 
the pterotic and sphenotic is visible both above and below the fossa. 
The post-temporal fossa is large and partially roofed, the roof being composed 
anteriorly of frontal and posteriorly of parietal and pterotic. The lateral wall and 
par 
10mm 
Fic. 87. Aulopus filamentosus. Neurocranium in ventral view. 
