Plate IX. 



Fig. GO. The same, still fai'tlier eaudad, showing the caudal portion of 

 the fenestral plate of the columella with its inner and outer bony plates. 



Fig. 61. Siren lacertina, adult. Section showing the columella, ceratohyale 

 the hyo-columellar ligament, into which projects the short stilus, and the 

 cartilaginous portion of the ear capsule tliat forms the perilymphatic prom- 

 inence. 



Fig. 02. The same, a few sections farther eaudad. The caudal end of the 

 stilus is in the ligament. The perilymphatic prominence ; position of artery 

 and vein. 



Fig. 03. The same, farther eaudad behind the fenestra and showing the 

 caudal portion of the perilympliatic prominence. 



