{ 379 ] 
XXVI. On the Osteology of the Marsupialia. By Ricuarp Owen, Esq., F.R.S., &c. 
Hunterian Professor of Anatomy at the Royal College of Surgeons. 
Communicated October 9, 1838. 
THE species of the Marsupial Animals can never be clearly defined or satisfactorily 
recognized, until their osteological characters, and more especially those derivable from 
the structure of the cranium, are accurately described and delineated ; and on this ac- 
count the following anatomical essay seems not inappropriate for the pages of the Zoo- 
logical Transactions. The experiments and observations which I had the opportunity 
of making some time ago', upon the generative ceconomy of the Marsupials, led me to 
pay more particular attention to the organization of this singular and interesting group 
of animals ; and I am induced to submit to the Society the result of my observations on 
the osseous system, both from its remarkable physiological modifications, and on ac- 
count of its application to the zoology of the Marsupialia. 
I have studied this part of the anatomy of the Marsupialia in the skeletons and skulls 
which are preserved in several museums in this country, as well as in the Museums of 
Comparative Anatomy at Paris and at Leyden; and although at first my object was 
simply to collect facts bearing upon the physiology, the affinities, and the specific cha- 
racters of the individual under examination, I was soon led, by a comparison of my 
notes, to appreciate a more general diffusion of certain remarkable osteological con- 
ditions than could have been anticipated from the varieties of form and locomotion in 
the different members of the marsupial group. 
As these general osteological conditions corroborate the inference which I have drawn 
from my investigations of the sanguiferous* and cerebral* systems of the Marsupialia, as 
to their natural association in a distinct group, and as some of the peculiarities of the 
skeleton at the same time illustrate the affinity of this group to the oviparous type of 
the vertebrate structure, I am induced to premise the following general observations on 
the osteology of the Marsupials* to the notices on the modifications of the skeleton in 
particular species and families, which I propose subsequently to communicate to the 
Society. 
Of the Skull.—The form of the skull varies much in different marsupial animals, but 
it may be said in general terms to resemble an elongated cone, being terminated by a 
1 Proceedings of the Zoological Society, 1833, p. 126, and Philosophical Transactions, 1834, p. 333. 
2 Physiological Catalogue, Museum of the Royal College of Surgeons, 1834, vol. ii. p. 52. 
3 Philosophical Transactions, 1837, p. 87. 
+ This memoir was communicated and read before the Prospectus (Avril 1839) of M. De Blainyille’s ‘ Osteo- 
graphie’ had appeared. 
