26 WILLIAM K. GREGORY 
\ Ip 
Yj 
- Lhe 
Fig. 18 Base of the skull, with lower jaw attached, of Cynognathus platyceps. 
Drawn from a cast of the type. 
The stapes (St.) is apparently displaced; according to Broom’s figure (P.Z.S., 1904, vol. 1, pl. xxxv, 
fig. I) it should be in contact with the quadrate. P 
e.a.m., auditory groove; p. ty. Sqg., post-tympanic process of squamosal. 
s 
take on an incipient auditory function before their old suspensory 
function had ceased. It was also suggested that the Weberian 
apparatus of Siluroid fishes offers a somewhat analogous case: 
where a tense vibrating sac had literally pressed into its service 
elements that had subserved originally a totally different 
function. 
5. It was pointed out (10a, p. 139) that the minute quadrate 
of Gomphognathus (fig. 11) resembles the incus of mammals: 
(a) in being a very small flattened bone located between the 
