[ 125 J 
VII. Synopsis of the species of recent Crocodilians or Emydosaurians, chiefly founded on 
the specimens in the British Museum and the Royal College of Surgeons. By Dr. 
Joon Epwarp Gray, F.B.S., V.P.ZS., ELS, &c. 
Read December 9th, 1862. 
[Paves XXXI. to XXXIV.] 
THE distinction of the species of Crocodiles has hitherto been one of the difficult 
problems in systematic zoology; and therefore I believe that it may be of some slight 
use to lay before the Society the result of my examination of the very large collection 
of Crocodiles, of all ages and from various localities, which are contained in the British 
Museum. Knowing the difficulty that surrounds the subject, I have made great 
exertions to obtain specimens from different countries; and the examination of these 
specimens has shown that the characters of the species, when allowance is made for the 
changes that take place in the growth of the animal, are quite as permanent as in any 
other group of Reptiles, and not more difficult to define. 
An outline of the synopsis of the Crocodilide or Alligatoride was published in the 
‘Annals and Magazine of Natural History’ for 1861 (5rd series, vol. viii.). Since that period 
I have examined the additional specimens which have been received in the British Museum, 
and also those in other collections, especially the skulls in the Museum of the Royal 
College of Surgeons, the specimens in the two museums at Liverpool, and in other local 
collections within my reach. Among the specimens recently received by the British 
Museum are some typical skulls from the Dutch possessions in the East, obtained 
from Leyden, which enable me to determine with certainty the species described by the 
Dutch zoologists. 
The determination of the species of the Crocodilians has always been attended with 
considerable uncertainty ; and if we may judge by the manner in which the specimens and 
the skulls of them are named in Museums, or sent about by the more scientific dealers, 
it would appear that as yet they are not properly understood. 
I do not mean as to the precise limit of a species—that is to say, whether the specimens 
from different districts of the same zoological or geographical province are mere local 
varieties of the same species, or are distinct; for that is a question which I admit must, 
with the materials at our command, for the present remain unsolved and open to discus- 
sion. But it is not unusual to find most distinct species confused under the same name, 
and specimens of the same species, only different in age, separated under two or more 
names. 
_ In this paper I have endeavoured to condense into a short synopsis the principal 
leading characters, especially those furnished by the examination of the skull and the 
VOL. VI.—PART IV. z 
