42 



MAMMA 



ig. OpofTum. 



18. 



Didelphis. 17. 



20. Mole. 



19. 



jTtf//«. 18. 



21. Shrew. 



20. 



Sorex. 19. 



22. Urchin. 



at. 



Ermaceus. 20 



IV. GLIRES. 





23. Porcupine. 



22. 



Hyjirix. 21. 



24. Cavy. 



2 3- 



Cavia. 



25. Beaver. 



24. 



Caftor. 23. 



26. Murine quadrupeds. 25. JVfw. 24. 



* Beaver-rats. 

 ** Rats and Mice. 



*** Hamfters. 

 **** Mole-rats. 



Myocafiores . 

 Mures. 



■J- Myofuri. 

 ff Cumcularii. 

 Criceti. 

 Myotalpae. 



27. Marmot. 



26. Arftomys. 



28. Squirrel. 



27. Sciums. 25. 



* Climbing Squirrels. S. Scandentes. 

 *'* Flying Squirrels. S. Volit antes. 



29. Dormoufe. 



28. Myoxus. 26, 



L I A. 



Ten fore teeth above, eight below. 

 Six fore teeth above, eight below. 

 Two fore teeth above, four below. 

 Two fore teeth in each jaw. The 

 body is b'efet with prickles. 



The body is covered with long fpines. 



The fore teeth are wedge like ; four 

 grinders on each fide. No col- 

 lar bones. 



The upper fore teeth wedge-like; four 

 grinders on each fide. Has collar 

 bones. 



The upper fore teeth wedgelike; 

 three grinders on each fide. Has 

 collar bones. 



The tail is flattened at the end. 

 The tail is round. 



With naked tails. 



With hairy tails. 

 Having cheek-pouches. 

 Have no external ears ; fmall eyes ; and 

 a very fhort tail, or none. 



Have two wedge-like fore teeth in 

 each jaw ; five grinders above, 

 and four below, on each fide. 

 Have collar bones. 



Have two wedge- like fore teeth above 

 and two, fharp pointed, below ; 

 five grinders above, and four be- 

 low, on each fide. Have collar 

 bones : Hair on the tail fhed fide 

 ways : Long whifkers. 



Have long whifkers ; and a round tail, 

 thick at the extremity. 



3°- 



