OEDEKS OF MAMMALIA. 



351 



their habits, but some are furnished with prehensile tails, and Hve 

 in trees. 4. Castoridre or Beaver family, comprising the Beaver. 

 The Beaver (fig. 2.5.5) has webbed feet and a scaly tail, and tlie fur 

 is an article of considerable value. It inhabits both North Anieiica 

 and Europe. The Musquasli resembles the Beaver in many respects, 

 and is also a native of Northern America ; but the Coypu is South 

 American. 5. Muridiv, comprising the Mice, Rats, Hamster, Lem- 

 mings, &c. The Rats and Mice are too well known to require more 

 than merely to be mentioned. 6. Dipodidif, conijirising the Jerboas 

 of the. Old World, and the Jumjsing Mice of America. 7. Mi/oxido', 

 comprising the Dormice, which must not be confounded with the 

 true Mice on the one hand, or with the Shrew Mice oa tlie other 

 hand. 8. Sciuridce, comprising tlie Scjuirrels, Flying Squiri-els, a)ul 

 Marmots. The Flying Squirrels do not really Hy, but like the 

 "flying" Phalangers, they take long leaps from tree to tree Ijy means 

 of laterally extended f(3lds of skin. The Marmots, unlike the ty])ical 

 Squirrels, are ground-animals, and live in burrows. An excellent 

 example is afforded by the Prairie-dog (Cijnomjs Ludoviciaiius) of 

 North America. 



ORUER XIV. CHEIROPTLRA. 



This order is uudovditedly one of the most distinctly circum- 

 scribed orders in the whole class of the Mammalia, and comjirises 

 only the Bats. 1\\ many respects, however, it might be well to 



'in), di Tluinili; rf.., Fore- 

 llar-boiie; / Thigh-bone ; 



regard the order as merely a modified branch of the Insectivora, just as 

 the Pinnigrada are regarded as a modified offshoot of the Candvora. 



