23 
a ridge on the external side of the skin of the animal, as 
though the neural spines already existed in the neck, and 
sharply elevated the soft tissues of the animal which covered 
them. • 
In the specimen No. 2 the forelimbs are also shown. On the 
right side they are short, flattened, lateral expansions, nearly as 
wide apparently as long, covered by two films super-imposed on 
each other. On the left side there is an obvious fracture, and 
what I suppose to be the limb seems to be nearly as deep as 
wide on its fractured surface, which is not mineralized with 
pyrites, but consists of clay. Behind the fracture the dorsal 
aspect of the limb appears to include a surface bone in the 
position of the ascending process of the plesiosaurian scapula. 
In this specimen, which rests upon No. 4, there is no 
clear indication of hind limbs, and the tail as exposed is 
exceedingly short, being shorter than in the specimen No. 1. 
The specimen No. 3, which is smaller, has not apparently any 
indication of the budding of limbs except a slight convexity at 
the base of the neck on the left side ; and in No. 4 the form of 
the body is distorted and cannot be regarded as giving conclu¬ 
sive proof of the existence of limbs. 
Hence the evidence for the interpretation of the specimen as 
embryos of plesiosaurs consists in the present state of preserva¬ 
tion of the fossil, in the form and proportions of specimen 1, 
which appears to indicate the head, neck, body, tail, and limbs 
of such a shape as a plesiosaur would show. Secondly, in the 
less perfect definition of the parts in the other specimens, which 
is such as might be expected in a group of embryos in various 
stages of development. Thirdly, in the community of character 
of the external structures, like the dorsal longitudinal ridge, 
seen in all the examples. 
Further, there appear to be some faint indications of trans¬ 
verse segmentation like that of muscles, in the region of the 
neck in the specimen No. 1, and in the dorsal region in 
specimen No. 2. 
The deficiencies of the evidence are the following :—The head 
in the specimen No. 1 terminates transversely in a truncated 
surface, rather like the nose in an Emydian Chelonian, instead 
of such a rounded nose as might have been expected. Secondly, 
