60 PK0CEED1NGS OF THE GEOLOGICAL SOCIETY.
was given by Prof. Cope in 1870 as a character of his genus
Elasmosaurus,a, very long-necked Plesiosaurian, to which, as already
Fig. 16. — Shoulder-girdle of Pliosaurus, Owen.
pc, the prsecoracoid ; co, the coracoid ; sc, the scapula ; gl t the glenoid fossa ;
/, the coraco -scapular vacuity.
said, Plesiosaurus Manseli, Pies, cliduchus, and Oolymbosaurus seem
nearly related. The present untrustworthiness of generic cha-
racters of Pliosaurus deduced from the propodial, epipodial, and
mesopodial segments of the limbs has already been shown. These
and similar delects in regard to the shoulder-girdle do not, however,
necessarily annul the genus, which, in spite of them, may survive
to afford another illustration of the Linnean aphorism, " Character
non facit genus, sed genus dat character."
The remaining four reptilian papers referred to members of the
subclass Dinosauria. Three of these were by Prof. H. G. Seeley.
One was a description of a sacrum, represented chiefly by a cast in
sandstone, remarkable for the large number (seven) of the vertebral
centra composing it, and for the lateral compression and height of
the neural canal. The same author, in another paper, brought
under our notice some thoracic vertebrae from Wealden rocks,
distinguished by the lateral compression of the centrum inferiorly,
which suggested the name Sphenospondylus. It is a form of ver-
tebra not uncommon at more than one horizon in the Wealden cliffs
of the south coast of the Isle of "Wight, from which I have myself
dug out several, one of which was associated with an Iguanodont
ischium. This and the close resemblance of their compressed
figure to that of the centra of the same part of the vertebral column
in Iguanodon Prestwichii led me to refer such vertebrae to a species