CATALOGUE 



OF 



SHIELD REPTILES. 



Order EMYDOSAURI (EMYDOSAURIANS). 



Emydosauri, Blainville. 



Gray, Ann. Phil. x. p. 195, 1825 ; Cat. Tortoises and 

 Crocodiles Brit. Mus. p. 38, 1844. 

 Crocodilia, Owen, Report on British Fossil Reptiles, Report 

 of Brit. Assoc-. 1841, p. 65. 



Huxley, Joarn. Proc. Linn. Soc. Zool. iv. p. 1. 



Head large, covered with a thin skin ; ears linear, closed 

 with two valves ; gape wide ; tongue short ; jaws with a 

 single series of conical teeth inserted in sockets and re- 

 placed by teeth formed beneath them ; hinder part of the 

 lower jaw produced behind the condyle ; nostrils small, 

 anterior ; eyes small. Throat with two glands. Keck 

 and sides of the body with a wrinkled skin, covered with 

 small tubercular scales. Back with a hard disk, formed 

 of longitudinal series of square, keeled, bony plates im- 

 bedded in the skin ; under surface covered with smooth, 

 thin, square plates ; back of the neck with two groups of 

 bony plates, the first called the nuchal, and the other the 

 cervical plates. Tail compressed, with two series of com- 

 pressed plates above. Vent longitudinal. Legs short ; 

 feet webbed ; toes 4-5, but only the inner 3 of each foot 

 clawed. 



Living in fresh and brackish water ; almost exclusively 

 in tropical climates. Eating animals which they have 

 killed by drowning. 



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 give 

 the result of the examination of the very large collection 

 of Crocodiles of all ages and from various localities which 

 are contained in the British Museum. Knowing the diffi- 

 culty that surrounds the subject, great exertions have been 

 made 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 Crocodilida? and Alligato- 

 ridse was published in the ' Annals and Magazine of Xatural 

 History' for 1862 (3rd series, vol. x.). Since that period 

 additional specimens have been examined 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 reach. 

 Among the specimens recently received by the British 

 Museum are some typical skulls from the Dutch possessions 

 iu the East, obtained from Leyden, which enable us to 

 determine with certainty the species described by the Dutch 

 zoologists. 



The determination of the species has always been at- 

 tended with considerable uncertainty ; and if we may 



B 



