312 MONOTREMATA. 



forming a remarkably fine and dense fur resembling 

 that of the mole, the other hairs are longer, have 

 the basal half fine like the under fur, but the apical, 

 exposed, half of each hair is dilated and flat, bent 

 at an angle with the basal portion, and is very 

 glossy, resembling the hairs of the seals. In these 

 longer hairs, being thin at the base, bent near the 

 middle, and expanded and stiff at the tip, we see a 

 beautiful provision suited to the habits of the animal. 

 When in the water the flat points become closely 

 applied together and afford a waterproof covering to 

 the fine under fur ; and when in its under ground 

 galleries, their peculiar texture and bent form permits 

 the animal to move either backwards or forwards 

 without inconvenience, and without exposing the 

 skin to the dirt. The hairs covering the tail are 

 very stiff and bristly ; on the upper surface they 

 point in various directions, and on the under surface 

 they are very short and closely adpressed ; in old 

 specimens the tail is frequently naked beneath, the 

 hairs being worn off. The toes of the fore-feet are 

 naked. The general colour of the Ornithorhynchus 

 is deep brown ; the under parts of the head and 

 body are pale brown ; the under fur is grey ; a small 

 whitish spot is observable in front of each eye. 



The dimensions of the specimen from which the 

 foregoing description is drawn up are as follows: 

 total length 23 inches measuring over the curve of 

 the back ; length of beak, 2^ inches ; width near 

 the tip, 1 inch 10 lines ; width at base, 1 inch 7 lines; 

 length of lower mandible, 1 inch 1 1 lines ; width at 



