116 



ILLINOIS BIOLOGICAL MONOGRAPHS 



[116 



EXPLANATION OF PLATE 

 Fig. 15. — Cranium of adult Amiurus, lateral view. 



Fig. 16. — Same, anterior end, ventral view, with vomer and parasphenoid removed. 

 Fig. 17, — Transverse section through occipital region of 8 mm. Amiurus. 

 Fig. 18. — Transverse section through ethmoid region of 8 mm. Amiurus. 

 Fig. 19. — Transverse section through roof of the anterior semicircular canal of 32 mm. 



Amiurus. 

 Fig. 20. — Adult cranium, lateral view. 

 Fig. 21. — Transverse section through fusion of occipital arch and parachordal plate, 8 mm. 



Amiurus. 

 Fig. 22. — Transverse section through anterior region of 32 mm. Amiurus. 

 Fig. 23. — Transverse section through the hypoglossal foramen of a 32 mm. Amiurus. 



