MUSCULAR SYSTEM 



177 



A, ventral view of male Or- 

 nithorhynchus ; B, ventral 

 view of male Echidna ; (7, 

 lateral view of the head 

 and neck of Echidna, all 

 the muscles shown in which 

 are supplied by the facial 

 nerve. 



Sphinct 



I" colli 



Fie. 138. A C, THE INTEGUMENTARY MUSCLES OF MONOTREMES. (After Ruge.) 



N 



