1886.] COLUMELLA OF I[CHTHYOSAURUS. 407 
long inferior border, decidedly marked off from a short posterior 
border, but the precise nature of its original articulation is unfortu- 
nately not apparent. The pterygoid seems to have slipped some- 
what from its natural position. 
Fig. I. Fig. 2. 
Fig. 1. Right columella of Zchthyosawrus, much crushed ; inner side view. 
[B.M., No. 2000. 40 * .] 
Fig. 2. Lower portion of right columella of Jchthyosaurus; outer side view : 
pi, pterygoid ; 0, crushed bones in orbit. [B.M., No. R 44.] 
Fig. 3. Lower portion of left columella of Ichthyosaurus intermedius; inner 
side view. [B.M., No. 2000. 15.] 
Fig. 4. Left columella of Hatteria punctata; outer side view: pt, pterygoid ; 
gu, quadrate. 
The fragmentary skull of Zchthyosaurus’ figured by Hawkins in 
his ‘ Book of the Great Sea-Dragons,’ pl. 19. fig. 1, also exhibits 
the lower two thirds of the left columella, and this is interesting as 
* This specimen has been identified with Z, intermedius, Conyb., by Sir 
Richard Owen, and bears his MS8, label, 
