Plate VI. 



Fig. 44. The same. Section farther caudad, showing the operculum, M. 

 opercularis and recessus perilymphaticus. 



Fig. 45. Gyrinophilus porphyriticus, adult. Section through the cephalic 

 end of the fenestra vestibuli and the distal end of the stilus columellse show- 

 ing its articulation. Note the relation of blood vessels and facial nerve. 



Fig. 46. The same. Section through the base of the stilus, a few sections 

 farther caudad. 



Fig. 47. The same. Several sections farther caudad, through the caudal 

 portion of the fenestral plate, opercular muscle and recessus. 



