406 MR. A. SMITH WOODWARD ON THE [June 29, 
other cranial elements in a more or less well-preserved state. Among 
the latter are two long bones with expanded extremities, lying 
lengthwise, one on either side of the basi- and presphenoids; and 
the form and situation of these elements, considered in connection 
with the evidence of other specimens presently to be noticed, can 
leave no doubt that they are the homologues of the columella 
(epipterygoid, Parker) found in Lacertilia, Khynchocephalia, Ano- 
modontia, Dinosauria*, and Chelonia. ‘The bone on the right shows 
a side view, while that on the left is seen either from behind or 
before, and although both are fractured to a certain extent, their 
boundaries are readily distinguishable. 
The right columella is 0°045 metre in total length, and is shown 
of the natural size in fig. 1*(p. 407). The upper end exhibits a tri- 
angular expansion, which, before fracture, must have measured about 
0-016 metre in greatest breadth ; and the long terminal upper border 
thus produced has a gently arched contour. Immediately below the 
expanded portion the bone becomes much constricted, having a 
diameter of only 0°003 metre, and at the distance of 0°019 metre 
from the lower extremity it commences again to widen, but here in 
am unsymmetrical manner. From the upper expansion downwards 
the anterior edge is nearly straight, but at the point just mentioned 
the hinder edge rapidly curves backwards, until the bone attains a 
maximum breadth of 0°012 metre, when the border once more 
descends almost vertically for some distance, and finally curves to the 
front. The lower end, however, has evidently been much crushed, 
like the remainder of the bone, and perhaps does not give an exact 
idea of its original shape. 
The left columella, presenting only an anterior (or hinder) view, 
does not add any further details to the foregoing description ; but 
this side of the fossil is of especial interest, since, as pointed out to 
me by Mr. G. B. Howes, there appears to be some indication of a 
downwardly-directed process of the parietal to meet the columella, 
such as exists in the living Cyclodus*. There is no indication of 
the fusion of the upper end of the bone with the parietal (or 
? “squamosal”’), such as Prof. Cope describes (/. ce. p. 204) in 
the American form. 
In a skeleton of Jchthyosaurus from the collection of the late Prof. 
Tennant (No. R 44 of the B.M. Register), the postorbital and 
adjoining bones are so far removed and displaced as to permit an 
admirable view of the lower end of the right columella, which is 
uncrushed, and still in contact with the pterygoid immediately 
behind the orbit. This is shown of the natural size in fig. 2. Its 
front edge is almost vertical, but curves slightly forwards near the 
lower termination, and there is a sharp anterior outer ridge along 
the whole length of the bone. The expanded portion exhibits a 
1 See O. C. Marsh, “ Restoration of Brontosawrus,” Amer. Journ. Scix(3) 
vol, xxvi. p. 83; ‘On the Diplodocide,” zbid. (3) xxvii. p. 163; “The Order 
Theropoda,” tom. cit. p. 332. 
? The drawings have been made by Mr. W. H. Hill. 
3 T. H. Huxley, ‘ Anatomy of Vertebrated Animals,’ p. 189, fig. 69. 
