47 
Sauropterygia — Plesiosauridce. 
Plesiosauridj:. — InWall-cases Nos. 9 and 10, and in Table- 
case No. 17, are placed the remains of one of our largest marine 
reptiles, the Pliosaurus, from the Kimmeridge Clay, near Ely, 
and also from Dorsetshire. W e have no entire skeleton of this 
animal, but the cast of a swimming-paddle (the original of 
Pliosaurus. 
Wall-cases, 
Nos. 9, 10. 
Table-case, 
No. 15. 
Fig.’’ 63. — Sauropterygian mandibles, a, Peloneustes philarchus (Seeley) ; from the 
Oxford Clay, g. b, Thaumatosaurus indicus (Lydekker), Upper Jurassic of India, }. 
c, Plesiosaurus dolichodirus, (Conybeare); from the Lower Lias, Lyme Regis, 
’which is preserved in the Dorchester Museum) measures 7 feet 
in length ; its jaw was 6 feet long, and one of its teeth was 15 
inches in length. It had a shorter neck than the Plesiosaurus , 
but was probably less fish-like in asjject than Ichthyosaurus , 
which latter reptile it outrivalled in 'point of size. 
In Wall-case No. 13, and in Table-cases Nos. 15, 16, 17, are 
arranged examples of the extinct group of marine reptiles, the 
Plesiosauria (see Fig. 67, p. 49). They are distinguished 
at once by the great development of the neck, which is composed 
of numerous vertebrae. The head is comparatively small in 
size; the orbits are large; the limbs being shaped externally 
Plesio- 
saurus. 
Wall case, 
No. 13, and 
Table-cases, 
Nos. 15, 16, 
17. 
