44 
THE DINOSAUEIA * 
By Professor H. G. SEELEY, F.R.S., F.G.S. 
[Plate II.] 
E XACTLY fifty years ago Hermann yon Meyer, the 
greatest comparative anatomist that Germany lias 
produced, recognized the fact that the extinct reptiles of the 
secondary strata have characters in common, which separate 
them from their living allies ; and he proposed to name the 
group Palseosauria. He further defined this sub-class of the 
Eeptilia as comprising three chief divisions ; first, flying 
animals, now termed Ornithosauria or Pterodactyles ; secondly, 
swimming animals, such as Ichthyosaurs and Plesiosaurs, 
which he named Hexipods ; and thirdly, animals resembling 
the larger and heavier land mammals, which he called Pachy- 
pods. These divisions were at once generally accepted, though 
the name Pachypoda has given place to Hinosauria. It is 
impossible to over-estimate the philosophical merit of Yon 
Meyer in dealing with these fossil remains, especially when 
their fragmentary nature is remembered ; and also bearing in 
mind the slow growth of knowledge which has enabled us to 
confirm and appreciate the truth of his views concerning the 
Dinosauria. 
Yon Meyer’s opportunities were almost limited to the study 
of fossils found in the Triassic rocks of Central Europe ; and 
owing perhaps to the slow diffusion of scientific information, the 
somewhat similar remains which were met with in the Wealden 
strata of the south-east of England were studied without 
regard either to the evidence furnished by German specimens, 
or to Y on Meyer’s generalization. 
* This lecture -was originally delivered on the 19th April, 1 879, at the 
Scientific Club in Vienna. An abstract of it, rendered in German by 
Count Marschall, has already been issued in the Monatsbldtter des wissen- 
schaftlichen Club in Wien. 
