32 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [ Nov. 24, 
1. On the Classification of the Dinosaurta, with observations on the 
Drnosavria of the Tatas. By T. H. Huxtzy, LL.D., F.R.S., Pre- 
sident of the Geological Society. 
[Prare IID. 
I. Tue CLAssIFICATION AND AFFINITIES OF THE DINOSAURIA. 
ContTENTS. 
1. The history and definition of the group. 
2. The establishment of the Order Ornithoscelida to include the Dinosauria 
and the Cempsognatha. 
3. The affinities of the Ornithoscelida with other Reptiles. 
4, The affinities of the Ornithoscelida with Birds. 
1. The History and Definition of the Group. 
Tue recognition of what are now commonly termed the Dinosauria, 
as a peculiar group of the feptilia, is due to that remarkable man 
whose recent death all who are interested in the progress of sound 
paleontology must deplore—Hermann von Meyer. In his < Paleo- 
logica,’ published so long ago as 1832*, Von Meyer classifies fossil 
reptiles according to the nature of their locomotive organs; and his 
second division, defined as ‘“‘ Saurians, with limbs like those of the 
heavy terrestrial Mammalia,” is established for Megalosaurus and 
Igquanodon. To this group Von Meyer subsequently applied the 
name of Pachypodes or Pachypoda. 
Nine years afterwards Professor Owen, in his “ Report on British 
Fossil Reptilia,” conferred a new name upon the group, and attempted 
to give it a closer definition, in the following passages :— 
“ Dinosaurians.—This group, which includes at least three well- 
established genera of Saurians, is characterized by a large sacrum 
composed of five ankylosed vertebree of unusual construction, by 
the height and breadth and outward sculpturing of the neural arches 
of the dorsal vertebree, by the twofold articulation of the ribs to 
the vertebree, viz. at the anterior part of the spine by a head and 
tubercle, and along the rest of the trunk by a tubercle attached to 
the transverse process only; by broad and sometimes complicated 
coracoids and long and slender clavicles, whereby Crocodilian cha- 
racters of the vertebral column are combined with a Lacertian type 
of the pectoral arch ; the dental organs also exhibit the same trans- 
itional or annectent characters in a greater or less degree. The 
bones of the extremities are of a large proportional size for Sau- 
rians; they are provided with large medullary cavities and with 
well-developed and unusual processes, and are terminated by meta- 
carpal, metatarsal, and phalangeal bones which, ‘with the exception 
of the ungual phalanges, more or less resemble those of the heavy 
pachydermal mammals, and attest, with the hollow long bones, the 
terrestrial habits of the species. 
““The combination of such characters, some, as the sacral ones, 
altogether peculiar among reptiles, others borrowed, as it were, from 
groups now distinct from each other, and also manifested by crea- 
* Von Meyer refers to the ‘Isis’ for 1830, as containing the first sketch of 
his views. J have not verified the citation. 
