588 



B. F. Kingsbury and H. D. Keed. 



loose connection of the stilus with the suspensorium, probably due 

 to the tilting of the latter in its relation to the long axis of the skull. 

 In Typhlomolge this tilting of the suspensorium is extreme and it 

 is, therefore, a fair question as to whether or not the segmentation 

 in the stilus is the result of tension during development. The attach- 

 ment of the stilus to both suspensorium and columella are at the same 

 horizontal level, there being a slight outward and downward curva- 

 ture as shown in Plate III, Fig. 28. 



The relation of the stilus to the blood vessels and nerves in this 

 region is that found in Necturus, namely, the vena petroso-lateralis 

 and the ramus jugular is of the facial nerve are above, while the main 

 trunk of the facial nerve and the internal carotid artery are below. 

 This condition is illustrated by Fig. 28 (PI. Ill) and Text- 

 figure 16. 



St. C.-^ 



Fig. 16. Typhlomolge, adult. Q., os quadratum ; R.j.VIL, Ramus jugularis 

 VII. ; St. C, stilus columella ; 8q., os squamosum. 



The fenestra vestibuli is irregularly elliptic in outline as is the 

 fenestral plate. The dorsal and ventral portions are not filled by the 

 plate, there being a relatively wide space both above and below filled 

 only by membrane. In the caudal portion there is a slight outward 

 swelling forming a prominence which projects slightly beyond the 

 caudal lip of the fenestra and which contains a small but well defined 

 recessus within. The M. opercularis is absent. 



The lips, both of the fenestra vestibuli and the fenestral plate. 



