XII 



PHYLUM CHORD AT A 



527 



9. Primates, comprising the lemurs, apes, and monkeys, 

 and the human species. 



The two genera of the Prototheria, Ornithorhynchus and 

 Echidna, differ somewhat widely from one another in gen- 

 eral appearance. The former (Fig. 314) has the surface 

 covered with a close soft fur, and has the upper jaw pro- 

 duced into a depressed muzzle, not unlike the beak of a 

 duck, covered with a smooth, hairless integument. The eyes 

 are very small, and there is no auditory pinna. The legs are 





FIG. 315. Spiny Ant-eater (Echidna acnleata). (After Vogt and Specht.) 



short, and the five digits end in strong claws, and are con- 

 nected together by a web, so that the limbs are equally 

 adapted for burrowing and for swimming. The tail is elon- 

 gated and depressed, covered with fur. The male has a 

 sharp-pointed, curved spur on the inner side of the foot, 

 having the duct of a poison-gland opening at its apex. 

 Echidna (Fig. 315) has the body covered above with 

 strong-pointed spines, between which are coarse hairs ; the 



