AUDITORY BULLA IX THE MUSTLLID.-E. 



Text-fio-nre 18. 



483 



A. Bulla of Taxidea opened from behind, sliowing; the nearly complete partition 



between the posterior and anterior chambers, and the extension of the 

 posterior into the external portion of the periotie. 



B. The same of Gvisonella sp. opened from below, showing the extension of the 



posterior chamber into the external portion of the periotic. 



C. The same opened from behind, showing the complete partition and the extension 



of the posterior chamber into the external portion of the periotic. 



D. Bulla of Mephitis opened from below showing the absence of partition, the 



arrow indicating the passage from the cavity into the hollow of the external 

 portion of the periotic. 



E. Hollow in external portion of periotic of Mephitis opened from the outside. 



F. The same of Conepatus. 



Lettering as in Text-fig. 15, with the addition of o, the orifice bj- which 

 the cavity of the bulla opens into the periotic hollow. 



