MANUAL OF NATURAL HISTORY. 31 



2. FAMILY. Duck-Bills (Ornithorhynchidse). Body 

 depressed, tapering at each extremity, clothed 

 with a mixture of crisp and soft fur ; muzzle 

 elongated, flattened, somewhat like a duck's- 

 bill, and covered with a thick skin ; tail short 

 and flat ; feet webbed, the membrane con- 

 tinued beyond the toes ; a spur on hind foot 

 of the males ; teeth horny. 



BIRDS. 



The arrangement chosen for this class, is that 

 employed by Mr. G. R Gray in his "Genera of Birds," 

 with such slight alterations as were thought to be 

 necessary. That arrangement appears to be the 

 best which has hitherto been brought forward, yet 

 much remains to be done by travellers and others, 

 having opportunity for making original observa- 

 tions, towards determining the natural affinities of 

 species and groups, which object can be greatly 

 aided by carefully recording, in detail, the habits of 

 such species as may come under their observation. 



Much has been written upon birds, by many 

 authors, both of ancient and modern date, though 

 the wonder is that more has not been written, for a 

 general interest seems to have been always felt in 

 them, which is not at all surprising, when we con- 

 sider the charm they lend to nature, and the sur- 

 prising manifestation of a beautiful adaptation of 

 means to ends exhibited in their conformation. 



