extrascapular series 

 postparietal 



postspiracular 



supratemporal 



parietal 



sclerotic ring 

 prefrontal^ 

 nasal series 

 septomaxilla 



internosals 



intertemporal 



premaxilla 



lateral rostra 



anterior and posterior splenial 

 A marginal gulars 



postcleithrum 



clavicle 



pectoral fin 



anterior palatine fenestra 



premaxilla. 



palatine /o". 



ectopterygoid. 



tip of 



notochord. 



parosphenoid 

 tooth plates 



B 



anterior medial gular^ 



internal nasal opening 



[A^interpterygoid fenestra 



^V^rostal part of 



parosphenoid 

 II 



hypophyseal fenestra 

 — pterygoid marginal gulars 



quodratojugal 



_ quadrate 



lateral canal 

 vestibular fontanelle 



posterior splenial 



supraongulor 



notochord canal 



Figure 4-28. Dermal head skeleton of Eusthenopferon. A, lateral view of head and pectoral girdle; 

 B, palatal view of skull; C, ventral view of head showing gulor area. (After Jarvik, 1944) 



CHOANATE FISHES • 93 



