Kincssury, Columella Auris and N. Facials. 319 
In the adult Spelerpes (Figure 3), the stilus is cartilagin- 
ous with a perichondral ossification continuous with the ossifi- 
cation of the operculum;—the cartilaginous core of the stilus, 
however, is distinct from the ring of cartilage within the 
operculum. 
i ——_——-— 
_>— 
Fig. 3. Spelerpes bilineatus, adult 67 mm. long. Section through the right 
otic capsule. c—Stilus columellae; o0—oral cavity; v. 7.—vena jugu- 
laris; @. m.—M. depressor mandibuli; S.—squamosum. 
The stilus passes forward, upward and slightly outward to 
the lower edge of the squamosum with which its cephalic end 
is joined by connective tissue (Fig. 3), and also with a small 
cartilage which lies upon the ventral edge of the squamosum. 
This cartilage extends forward for about 150 microns and is 
cylindrical. It is free at its caudal end, which articulates with 
the stilus, and fused with the ventral edge of the squamosum. 
The stilus and operculum are at about the same level. The 
former lies at first upon the dorsal side of the external semi- 
circular canal, gradually moving down to the lateral surface of 
the otic capsule, as it is traced forward. As it continues to 
