Plate XLM 



Comparative Series: Left Inner and Middle Ear of Aides and Propitlwciis 

 Specimens and stereoscopic views prepared by Mr. A. E. Anderson. X f. 



1. Ateles sp. Amer. Mus. No. 6336. Part of inner and middle ear of tlie left side, after the removal of the lower part of the bulla, 

 showing the middle ear, with the ossicles in situ, the interior of the bony cochlea, and the cellulae petrosse of the hypotympanic sinus. 



Fropitkecus 



2. Propiihecus coquerelli. Amer. j\Ius. No. 31255. Inner and middle ear of the left side. Exposure of the cochlea, hypotympanic 

 sinus, cavum tympani, attic {rec. epity.), etc., after removal of the lower part of the bulla, tympanic annulus, membrana tympani, mal- 

 leus, and incus; the stapes (st) being left in situ. The bristle shows the course of the internal carotid canal (arteria promontorii). 



