PACHYDERMATA. 97 



the superior extremity of the horny beak; the neck is short, and 

 the general form of the body is nearly cylindrical. The fore feet 

 have a membrane which not only unites the toes, but is carried 

 considerably beyond the nails ; on the hind feet the membrane 

 terminates at the root of the nails. As might be anticipated from 

 what we have said of their conformation, the Oruithorynchi are 

 aquatic animals ; they inhabit the marshes and rivers in the in- 

 terior of New Holland, and live like ducks, (if we may thus apply 

 the word,) by sifting the mud to separate from it insects and larva?. 

 The species best known is the Ornithorynchus Paradoxus. 



ORDER OF PACHYDERMATA. 



13. The animals comprised in this order are remarkable for the 

 hard thick hide with which most of them are covered : they are 

 nnyulatc mammals, (that is, the extremity of the foot is enveloped 

 in a very large nail, constituting a hoof;) they have generally a 

 simple stomach and do not ruminate. 



14. Their teeth present great varieties in form and structure ; 

 in some, the incisors are trenchant, in others they are wanting ; 

 and in others again they are replaced by tusks. The same is true 

 of the canines ; while some resemble ordinary canines, others be- 

 come powerful and dangerous defensive weapons, and others 

 again want them altogether. The molars have wide irregular 

 surfaces suited for grinding. 



15. They are entirely without a clavicle and are incapable of 

 bending the fingers (toes) which are in number either five, or three, 

 or only one, and rarely two. The Order of P achy dermal a in- 

 cludes the largest terrestrial mammals known. Except the Horse, 

 they are all clumsy, and have a heavy, indolent gait ; are very 

 dirty, and particularly fond of wallowing in the mud ; they con- 

 tinually dwell in troops, in warm covered places, in marshy situa- 

 tions, where they find aquatic stalks and roots suited to their wants; 

 sometimes the neck is very short, but then, as in the case of the 

 Elf pliant, they are provided with a trunk capable of raising from 

 the ground all objects which they wish to convty to the mouth ; 

 or, remaining almost constantly in the water, they can, without 

 stooping, catch the leaves and stalks floating on its surface. 



13. How are animals of the order of Pachydermata characterised? Do 

 they chew the cud? 



14. What is the character of the dental system of animals of this order ? 



15. What kind of a clavicle have the Pachydermata ? What is the num- 

 ber of their toes ? What are their general habits ? 



