emed anchylosed, as in quadrupeds,
into one bone; and there remained no scar to show that the suture had
ever existed. In some specimens the ribs seem to have been articulated
to the sides of the centrum; in others there is a transverse process,
but no marks of articulation. Some of the vertebrae are evidently dorsal,
some cervical, one apparently caudal; and almost all agree in showing in
front two little eyelets, to which the great descending artery seems to
have sent out blood-vessels in pairs. The more entire ribs I was lucky
enough to disinter have, as in those of crocodileans, double heads; and
a part of a fibula, about four inches in length, seems also to belong to
this ancient family. A large proportion of the other bones are evidently
Plesiosaurian. I found the head of the flat humerus so characteristic of
the extinct order to which the Plesiosaurus has been assigned, and two
digital bones of the paddle, that, from their comparatively slender and
slightly curved form, so unlike the digitals of its cogener the
Ichthyosaurus, could have belonged evidently to no other reptile. I
observed, too, in the slightly curved articulations of not a few of the
vertebrae, the gentle convexity in the concave centre, which, if not
peculiar to the Plesiosaurus, is at least held to distinguish it from
most of its contemporaries. Among the various nondescript organisms of
the shale, I laid open a smooth angular bone, hollowed something like a
grocer's scoop; a three-pronged caltrop-looking bone, that seems to have
formed part of a pelvic arch; another angular bone, much massier than
the first, regarding the probable position of which I could not form a
conjecture, but which some of my geological friends deem cerebral; an
extremely dense bone, imperfect at each end, which presents the
appearance of a cylinder slightly flattened; and various curious
fragments, which, with what our Scotch museums have not yet
acquired,--entire reptilian fossils for the purposes of
comparison,--might, I doubt not, be easily assigned to their proper
places. It was in vain that, leaving John to collect the scattered
pieces of shale in which the bones occurred, I set myself again and
again to discover the bed from which they had been detached. The tide
had fallen, and a range of skerries lay temptingly off, scarce a hundred
yards from the water's edge: the shale beds might be among them, with
Plesiosauri and crocodiles stretching entire; and fain would I h