r 125 ] 



VII. Syno]}sis of the species of recent Crocodilians or 'Emydosa.uria.ns, chiefiy founded on 

 the specimens in the British Museum and the Boyal College of Surgeons. By Dr. 

 John Edward Gray, F.B.S., V.P.Z.S., F.L.S., &c. 



Read December 9th, 1862. 



i.u^Ai^> 



/d>€^. 



[Plates XXXI. to XXXIV.] 



i HE 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. Knov^'ing the difficulty that suiTounds 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 pennanent as in any 

 other group of Eeptiles, and not more difficult to define. 



An outline of the sjoiopsis of the Crocodilidae or Alligatoridae was published in the 

 'Annals and Magazine of Natural History' for 1861 (3rd series, vol. viii.). Since that period 

 I have examined the additional specimens which have been received in theBritish 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 wovild 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 pruicipal 

 leading characters, especially those furnished by the examination of the skull and the 



VOL. VI. PART IV. T 



