THE DUCKBILL 



1457 



external conchs to the ears, and the eyes are small, and in the living state incon- 

 spicuous. The tail is broad and somewhat flattened, with a coat of coarse hairs, 

 which on the under surface become more or less worn off in old individuals. The 

 short limbs have their feet more especially the front pair expanded and webbed 

 for the purpose of swimming. Each foot has five complete toes furnished with 

 strong nails; but while in the fore-feet the web extends considerably beyond the 

 extremities of the nails, in the hind-pair it reaches only to their bases. The exten- 

 sion of the web of the fore-feet might appear to be a hindrance in burrowing; but 

 this difficulty is avoided by the web being then folded back on the palm of the paw. 

 The nails of the fore-foot are somewhat flattened and expanded, while those of the 

 hind-foot are longer, narrower, and much curved. To the heel of the male is 



THE DUCKBII.I,. 

 (One-fourth natural size.) 



affixed a long, horny spur, curving upward and backward, and nearly an inch in 

 length. A canal traversing this spur, and opening near its summit, is connected 

 with a gland on the leg, which appears to secrete a poisonous fluid. 



The tongue is small and nonextensile; while the cheeks are provided with 

 pouches of considerable size, doubtless used for storing food. If it be a fully adult 

 specimen that we examine, it will be found that in lieu of teeth each jaw carries 

 two pairs of horny plates, of which the more anterior are sharp and narrow, while 

 those behind are broad and flattened. Between these plates the palate is thrown 

 into a number of transverse wrinkles, like those in a duck. In young specimens, 

 however, two or three pairs of cheek-teeth may be observed in the upper, and two 

 pairs in the lower jaw; most of these teeth being broadly quadrangular in form, 

 92 



