THE CHELONIA,. 1017 
that it is preserved in a relatively soft matrix and has been so 
macerated before burial that the ribs have twisted round on their 
articulations so as to lie nearly flat. 
It shows one pubis and a femur, tibia, and fibula, 
Skull—The skull is very incompletely and rather badly pre- 
served. 
The basisphenoid is broad and provided with basipterygoid 
processes directed forwards in the plane of its flat lower surface. 
There is a rather wide parasphenoid. 
The quadrate clearly lies considerably in advance of the occipital 
condyle. There are numerous teeth on the palate, some scattered, 
but most forming a ridge on the pterygoid. The choane are 
rather large and separated by wide bars of the prevomers, lying 
close up to the maxille and premaxille. 
The maxilla is provided with a single series of small round (?) 
teeth, of which about eight are shown. 
The premaxille also bear teeth, apparently three in each. 
When I first saw the specimen the whole of the extreme 
anterior end of the skull was covered by matrix, which I removed 
with a needle under a Zeiss binocular dissecting microscope. 
Whilst doing so I found no trace whatever of any internarial 
processes of the premaxille, and believe them to have been 
certainly absent; the anterior nares are consequently confluent 
and look directly forward. 
The lower jaw is present but not sufficiently well shown for 
description. 
Except for the evidence given by specimen No. 49424, that the 
neck was relatively long and very flexible, nothing is known of 
this part. 
R. 4054 which, as shown by the position of the limb-girdies, 
has a complete dorsal region, has ten dorsals. These are all fairly 
similar in structure. The first is short, the second somewhat 
longer, and the third very long. The fourth, fifth, and sixth are 
about as long as the third, and the seventh to the tenth show a 
progressive diminution in length. The structure of the individual 
vertebrae is best shown by the type-specimen. The centrum is 
very slender, particularly in the fourth to seventh dorsals, and 
somewhat hourglass-shaped; it is completely pierced by the 
notochordal canal. The rib-facet is carried on a very low and 
small process which in the middle dorsal region is placed at the 
extreme anterior end of the centrum, whilst anteriorly and 
posteriorly it travels back to the middle of its length. The 
neural arch is rather massive when compared with the centrum 
but is still very narrow. It bears very narrow zygapophyses 
which seem to interlock strongly. The upper surface of the 
neural arch is essentially flat, the spine being represented only by 
a low median ridge. The whole arch appears to be placed very 
far forward on the centrum and may overlap on its anterior end. 
There is no definite transverse process, but the ribs seem to touch 
the sides of the neural arch. 
