2 ORNITHORHYNCHIDjE. 



Family I. ORNITHORHYNCHIIXE. 



Muzzle in the shape of a broad, flattened, horny beak. Tongue 

 not extensile. Fur not mixed with spines. Tail well developed, 

 broad, and flattened. Hands and feet modified as swimming- 

 organs, the toes broadly webbed. Palms and soles naked, without 

 pads. Teeth rudimentary, only found in young animals, in which 

 there are two on either side of the upper jaw and three on either 

 side of the lower jaw, these being persistent till the animal is 

 rather more than one-third grown ; never cutting the gum ; multi- 

 cuspid ; replaced in the adults by strong, horny plates. Cerebral 

 hemispheres smooth. 



Genus I. ORNITHORHYNCHUS, Slunienbach (1800). 



Form elongate and depressed. Toes 5 5, all with long claws, 

 which on the fore feet are broad and blunt, on the hind feet 

 compressed and pointed. Beak short, with a basal projecting 

 leathery flap both above and below. Cheeks pouched. 



Vertebras. C. 7, D. 17, L. 2, S. 2, Cd. 20 or 21 = 48 or 49. 



Habits. Aquatic ; fossorial ; feeding on crustaceans, mollusks, 

 water-insects, worms, &c. 



Note. Under the name of Ornithorhynchus agilis, Mr. C. W. 

 De Vis has described (Proc. Roy. Soc. Queensland, 1885, p. 35, 

 pi. iv.) from a right tibia and the distal half of a right mandible, 

 what appears to be a very distinct species of fossil Platypus ; re- 

 versing the general laws in such cases, this extinct species, which 

 from the dentition is unquestionably adult, must have been of a 

 considerably smaller size than its living representative. The 

 fossils were excavated on King's Creek, au affluent of the Conda- 

 mine River, near Pilton, South Queensland. Shaw's name Platypus 

 (1799) having been employed by Herbst six years previously for 

 a genus of Coleopterous Insects is inadmissable. 



1. ORNITHORHYNCHUS ANATINUS, Shaiv, sp. (1799). 

 Duck-billed Platypus ; Water Mole. 



Male much larger than female. Fur short, close, and velvety. 

 General color above deep umber- or blackish-brown ; below 

 grayish-white ; a white or yellowish spot round the eye ; tail 

 colored above like the back, generally naked below ; bill black 

 above, yellow and black below. 



Dimensions. Head and body of male, about eighteen, of female 

 about fourteen inches ; tail of male about six, of female about 

 five inches. 



Habitat. Queensland southwards of 18 S. lat., New South 

 Wales, Victoria, South Australia, and Tasmania. 



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