24 
the pre-orbital region curves downward, and there does not 
appear to be any demonstrable indication of a mandible. An 
injury crosses the head from behind the right orbit forward, so 
as to break the continuity of the front of the head with its 
hinder part in such a way that, taken by itself, the identification 
of the head is not quite conclusive in the present state of 
preservation, notwithstanding some longitudinal markings like 
definition of the nasal and other skull bones. It is possible that 
the extremity of the snout is broken and lost, and that the 
lower jaw may be indicated in the film of clay, which is im¬ 
perfectly preserved beneath the head, and that some small 
badlv preserved white spots arranged in linear succession are 
indications of teeth. By the side of this head there is 
the anterior termination of another imperfect specimen which is 
possibly a head also. If so it terminates in a sharp point, com¬ 
pressed laterally and flattened above, and is manifestly much 
less developed ; but I am unable to recognise indications of any 
parts of the head or its organs. The curvature of the head 
upon the neck is however similar in the two specimens. 
These defects in the preservation of the specimens do not 
appear to me to be conclusive against the organic nature of 
these supposed embryonic Plesiosaurs; and I have stated them 
as fully as possible that there might be no acceptance of the 
interpretation which I have placed upon the specimen, without 
consideration of the grounds on which that interpretation may 
be questioned. 
The following descriptions record the dimensions of the 
several specimens :— 
I. 
The extreme length of the specimen No. 1 measured along 
the middle line is 5 inches. The head measures JJ of an 
inch, the neck is 1, 8 0 of an inch long, the body is about 1, 6 0 of an 
inch, and the tail as exposed is , 6 0 of an inch long. 
The head appears to be long, narrow, contracting in front of 
the orbit, about a quarter of an inch deep posteriorly, and 
half that depth at the anterior termination of the snout. The 
two sides of the head are inclined to each other, and its summit 
is rounded much as in many plesiosaur skulls. Its lateral 
aspect is a good deal modified by the loss of the radiated circle 
