pterygoid 



grooves of 

 nasal openings 



olfactory nerve foramen 



quadrate 



parasphenoid 

 cranioquodrate fissure A^- 



ophthalmic artery 

 hypophyseal fenestra 



efferent pseudobranchiat 

 artery 



orbital artery 



groove of radix aortoe 



notochord canal 

 foramen magnum 



B 



orbital artery 



anterior cerebral vein 

 orbitonasal foramen, V 



parasphenoid 



ophthalmic artery 



pituitary vein' 



spinoccipital foramina 

 prearticular tooth plate 



middle cerebral vein 



ramen magnum 

 otochord canal 



efferen 



dentary 



posterior 



spleniol 



angular 



Figure 4-37. Endocranium and jaws of Dipterus. Endocranium reconstructed from that of Chiro- 

 dipterus (described by Save-Soderbergh, 1952). A, palatal view of skull; B, ventral view of endo- 

 cranium; C, lateral view of endocranium; D, medial view of right half of endocranium; E, dorsal view 

 of lower jaw. 



CHOANATE FISHES 



101 



