88 



ILLINOIS BIOLOGICAL MONOGRAPHS 



[88 



EXPLANATION OF PLATE 



Fig. 64. — Transverse section through the planum basale of Necturus maculatus 30 mm. long. 

 Fig. 65. — Transverse section through the posterior part of the fenestrated process of Necturus 



maculatus 45 mm. long. 

 Fig. 66. — Transverse section through the planum verticale of the younger larva of Epicrium 



glutinosum. 

 Fig. 67. — Transverse section through the same region of a 90 mm. Epicrium. 

 Fig. 68. — Transverse section through the planum basale of the same animal. 

 Fig. 69. — Transverse section through the planum verticale of the older Amphiuma means larva 

 Fig. 70. — Transverse section anterior to the planum verticale of Amphiuma means 82 mm. 



long. 

 Fig. 71. — Transverse section through the planum basale of the same animal. 

 Fig. 72. — Transverse section through the anterior planum basale of a larva of Pipa americana. 

 Fig. 73. — Transverse section slightly posterior to the above. 

 Fig. 74. — Transverse section through planum verticale of Pipa americana. 

 Fig. 75. — Transverse section through the choanal region of Pipa americana. 

 Fig. 76. — Transverse section through the external naris of Hyla pickeringii. 



al p alary process 



anc alinasal cartilage 



ce columna ethmoidalis 



ch choana 



ct cornu trabeculae 



e ethmoid bone 



en external naris 



eng external nasal glands 



Jen nb fenestra naso-basalis 



Jen pr fenestrated process 



fr frontal 



ig intermaxillary gland 



jo organ of Jacobson 



le lamina externa 



m maxillary bone 



n nasal bone 



no nasal organ 



oc oblique cartilage 



