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ILLINOIS BIOLOGICAL MONOGRAPHS 



1118 



EXPLANATION OF PLATE 

 Fig. 24. — Transverse section through lower jaw of 60 mm. Amiunis, midway between 



s>'mphysis and quadrate articulation. 

 Fig. 25. — Similar section, 32 mm. Amiurus. 

 Fig. 26. — Transverse section through the parachordal plate ventral to the vagus foramen, 



32 mm. Amiurus. 

 Fig. 27. — Transverse section through anterior end of parachordal, 32 mm. Amiurus. 

 Fig. 28. — Same, a little farther posterior. 



Fig. 29. — Transverse section through posterior part of occipital arch, 32 mm. Amiurus. 

 Fig. 30. — Transverse section through ethmoid region, 8 mm. Amiurus. 

 Fig. 31. — Transverse section through roof of lateral semicircular canal, 32 mm. Amiurus. 

 Fig. 32. — Transverse section through posterior orbital region, 32 mm. Amiurus. 



