620 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [June 22, 
closely resemble those of this Kimmeridge Plesiosawrus; and the 
points of similarity are just those wherein this departs from the 
Liassic types. 
I find, on comparing them, a very close general and particular 
agreement between the humerus and femur of the Kimmeridge 
Plesiosaurus and two type specimens in the British Museum, 
labelled “‘ No. 31,795. Femur, Plesiosaurus trochanterius, Owen,” 
and “No. 31,787, femur of Plesiosaurus brachydeirus, Owen.” No. 
31,795 is smaller than the Kimmeridge humerus, but in all other 
respects closcly resembles it. It has the same general form, arti- 
cular caput, trochanter and separating groove, and the rough warty 
muscular impression on the ventral surface and postaxial border. 
The preaxial and first postaxial segments of the distal border are 
inclined at a similar angle; the preaxial segment is similarly con- 
cave. The remainder of this and the distal part of the postaxial 
border, including the wing, are unfortunately wanting, so that the 
comparison cannot be completed. 
The Kimmeridge Plesiosaur’s femur is extremely like No. 31,787, 
a femur of ‘‘ Plesiosaurus brachydeirus, O.,” a longer bone (from a 
larger individual ?), but with outlines which, so far as they are pre- 
served, closely resemble those of the Kimmeridge Plesiosaurus. At 
first sight most striking differences are a greater axial symmetry 
due to the smaller size of the wing, and the subdivision of the distal 
end into two facets only; but it only requires a second glance to 
see that the distal third of the postaxial border, with the corre- 
sponding part of the wing and of the distal border, have been broken 
off, and the rough fractured edge smoothed with plaster of Paris. 
It has a similar articular caput, separated by a groove running 
between the preaxial and postaxial borders from a strongly formed 
trochanter. The preaxial and so much as remains of the postaxial 
division of the distal end are inelined at a like angle, and each is 
similarly concave. 
When the comparison is extended to the second and third seg- 
ments of the limb, similar resemblances are apparent. The paddles — 
available for this purpose are two—the well-known enormous 
paddle of Phosaurus grandis, presented to the Dorchester Museum 
by its discoverer and restorer, Mr. J. C. Mansel, and the small paddle 
of Phosaurus portlandicus in the British Museum, described and 
figured by Professor Owen in the Palzontographical Society's Me- 
moirs, vol. xxu.* 
In both these we notice the same formal indifferentism of the 
bones composing the cnemion and tarsus, and, the same transverse 
extension of the tibia and fibula. In the Dorchester paddle, an excel- 
lent cast of which is in the north gallery of the British Museum, the 
femur is mutilated. It manifestly wants a great part of the wing, 
which has been split off by a straight fracture parallel to the axis 
running from the postaxial to the distal border. The tibia and 
fibula support flat multiangular tarsals, which are succeeded by five 
* Fossil Reptilia of the Kimmeridge Clay, genus Plesiosaurus, by Prof. Owen 
(Paleontogr. Soc. Mcm. vol. xxii. for 1868), pl. 4. fig. 1. 
