22 



bulletin: museum of comparative zoology. 



EXPLANATION OF PLATES. 



Abbreviations . 



interneural. 



interopercle. 



maxillary. 



ossified ligament. 



opercle. 



parietal. 



postclavicle. 



prefrontal. 



premaxillary. 



preopercle. 



posttemporal. 



parasphenoid process. 



prootic. 



parasphenoid. 



pterotic. 



pterygoid. 



supraclavicle. 



supraoccipitaL 



subopercle. 



sphenotic. 



symplectic. 



vomer. 



vertebra. 



