378 



MR. R. I. POCOOK ON THE EXTERNAL 



Text-figure 6. 



Ear of Myocastor coypus, with haivs removed. 



Lower portion of the same with vertical cut throxigh the intertragal notch, 



and the tragus turned forwards to show the fringe of hairs above the 



orifice and the tuft of hairs on the antitragus {a). 

 Ear of DretJiizon dorsatum, with the hairs removed. 



,, Coendu prehensilis, 



„ Dinomys branickii, copied from Peters. 



„ IDasi/procta sp. ? 



,, Cavia aperea, with valvular flap upturned below supratragus. 



„ Galea littoralis, without valvular flap below supratragus. 



„ Octodon degus. 



,. Loncheres armatus, copied from Wmge. 



,, TScliimys cajennensis, copied from Winge. 



,, Ctenomys mendocinus. 



„ Ctenodactylns fftindi. 



a, antitragus; s, supratragus. 



