PROM THE LOWER LIAS OF CHARMOUTH. 



441 



the " furculum," or combined clavicles, is tilted up from right 

 to left. 



So far as the appendicular skeleton is concerned, it has approxi- 

 mately the position it would have in an animal lying flat on its back 

 with its limbs extended outwards, except that it has been skewed 

 over as a whole a little to the left, and the right fore limb completely 

 crossed over. 



The axial skeleton is similarly disposed as far as the ribs are con- 

 cerned ; but the head and vertebral column have been turned round 

 9u°, and lie on one side, the left. The neck and head are also 

 curved backwards, in the manner so usual with Plesiosaurus, and 

 which has been commented on by Professor Huxley as suggestive of 

 death by opisthotonic contraction. 



This disposition of the parts of the skeleton may be readily ex- 

 plained by supposing that the animal to which it belonged fell, after 

 death, sideways through some depth of sea-water to an oozy bottom. 

 The body , being broadest laterally, has settled on its back, the hind limbs 

 sprawling outwards. The left shoulder touched the bottom first ; and 

 the right fore limb heeling over, fell across the one to the left. The 

 neck and, in this species, the head being broadest dors o-ventr ally, 

 settled on one side, the left, and so communicated a twisting strain 

 to the rest of the vertebral column, which, being but slightly attached 

 to the ribs and appendicular skeleton, readily yielded to it, and 

 turned on its side also ; thus the whole of the vertebral column 

 came to lie on its broadest face (that is to say, laterally). The twist 

 to the left given by the crossing of the right fore limb, and the sub- 

 sequent pressure of overlying strata, led to the various other minor 

 dislocations and displacements. 



That the specimen is undoubtedly the type of a new species is 

 shown by the following summary of its chief characters : — 



1. The length of the skull from the anterior extremity of the 

 lower jaw to the posterior margin of its articulation with the qua- 

 drate bone is 19-75 inches, measured along the right side. 



2. The number of vertebras is 66, of which 59 are cervico-dorsal, 

 2 sacral, and 5 caudal. Of the cervico-dorsal vertebras 38 appear 

 to be cervical and 21 dorsal. 



3. The length of the cervical region is 83 inches (6 feet 11 inches); 

 so that the length of the head is to that of the neck as 24*1 : 100. 



4. The length of the cervico-dorsal series is 136 inches (11 feet 

 4 inches) ; and the length of the head to this is as 14-6 : 100. 



5. The length of the centrum of the anterior cervical vertebras is 

 equal to the height and greater than the breadth of the articular 

 face. Thus in vertebra xv the measurements are : — Length 2 inches, 

 breadth 1*5 inch, height 2 inches. 



6. In the posterior cervical vertebras the breadth of the articular 

 face is greater than the length or height, but the latter two dimen- 

 sions remain equal. Thus in vertebra xxxv we find — length 2*7 

 inches, breadth 3*5 inches, height 2*7 inches. 



7. The neural spines increase in size up to the 40th to 44th ver- 

 tebra, in which they measure 4*75 inches in length. 



