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ILLINOIS BIOLOGICAL MONOGRAPHS 



[90 



EXPLANATION OF PLATE 



Fig. 77. — ^Transverse section posterior to the external naris of the adult Hyla pkkeringii. 



Fig. 78. — ^Transverse section through the lamina externa of the same animal. 



Fig. 79. — ^Transverse section through the choana of a 9 mm. Bufo americana. 



Fig. 80. — ^Transverse section through the fenestra naso-basalis of Bufo. 



Fig. 81. — ^Transverse section slightly anterior to the preceding section. 



Fig. 82. — ^Transverse section through the external naris of the same animal. 



Fig. 83. — ^Transverse section through the muscularis process of the quadrate of Rana vtridescens 



28 mm. long. 

 Fig. 84. — ^Transverse section through the pons ethmoidalis of the same animal. 

 Fig. 85. — ^Dorsal view of model of the nasal capsule of a yoimg adult of Rana vtridescens. 

 Fig. 86. — Side view of model of the nasal capsule of the same animal. 



amp anterior maxillary process 



anc alinasal cartilage 



cc cavum cranii 



ce columna ethmoidalis 



ck choana 



cr s crista subnasalis 



cr t crista trabeculae 



fen nb fenestra naso-basalis 



fon foramen orbito-nasalis 



/* frontal branch of superficialis 



ig intermaxillary gland 



ipe inferior prenasal cartilage 



jo organ of Jacobson 



Id lacrimal duct 



