monsters which received their
name from the peculiar structure of their teeth. He published
elaborate descriptions of Anthracosaurus from the coal-measures of
Northumberland, of Loxomma from the lower carboniferous of Scotland,
and of several small forms from the coal-measures of Kilkenny, in
Ireland, as well as describing skulls from Africa and a number of
fragmentary bones from different localities. But in all this work it
was the morphology of the creatures that interested him, and the light
which their structure threw upon the structure of each other and of
their nearest allies. He shewed that these monsters stood on the
borderland between fishes, amphibia, and reptiles, and he added much
to our knowledge of the true structure of these great groups. Next, he
turned to the extinct reptiles of the Mesozoic age. It was generally
believed that the Pterodactyls, or flying reptiles, were the nearest
allies of birds, but Huxley insisted that the resemblances between the
wings were simply such superficial resemblances as necessarily exist
in organs adapted to the same purpose. About the same time, Cope in
America, and Phillips and Huxley, in England, from study of the bones
of the Dinosaurs, another great group of extinct reptiles, declared
that these were the nearest in structure to birds. In association with
the upright posture, the ilium or great haunch-bone of birds extends
far forwards in front of the articulation of the thigh-bone, so that
the pelvis in this region has a T-shape, the ilium forming the
cross-bar of the T, and the femur or thigh-bone the downward limb.
Huxley shewed that a large number of the Dinosaurs had this and other
peculiarities of the bird's pelvis, and separated these into a group
which he called the "Ornithoscelida," seeing in them the closest
representatives of the probable reptilian ancestors of birds. While
further work and the discovery of a still greater number of extinct
reptiles has made it less probable that these were the actual
ancestors of birds, Huxley's work in this, as in the many other cases
we have shown, proved not only of great value in itself, but led to a
continually increasing series of investigations by others. It is not
always the pioneer that makes the greatest discoveries in a new
country, but the work of the pioneer makes possible and easier the
more assured discoveries of his followers.

A third great piece of palaeontological investigation with which the
name of Hu