MANUAL OF NATURAL HISTORY. 27 



lindrical ; tail absent or very short ; limbs 

 short ; cutting teeth often very large. 



6. FAMILY. Spiny-Rats (Echimyidse). Facial line 



slightly curved ; nose generally blunt, some- 

 times rather produced, giving a more murine 

 aspect; tail usually very long, scaly, but 

 more or less clothed with hair, occasionally 

 forming a brush at end; body clothed with 

 fur, more or less intermixed with strong, 

 grooved, lance-like spines, or with longer and 

 larger hairs, which are flattened and grooved 

 like the spines; molars with flat crowns. 



7. FAMILY. Porcupines (Hystricidae). Body more 



or less armed with spines ; muzzle broad, 

 thick, clothed with soft hairs ; facial line 

 rather hollow between eyes and nose ; upper 

 lip slightly notched or divided by a vertical 

 groove ; tail short, and furnished with spines, 

 or long, more or less destitute of hair at 

 apical portion and prehensile; soles of feet 

 naked and smooth, and having five toes, or 

 with expanded and rough soles, and toes 

 45 or 44. 



8. FAMILY. Chinchillas (Chinchillidse). Head 



broad; eyes placed far back ; whiskers long; 

 ears large, rounded or elongated; tail long 

 or moderate, recurved and bushy; toes 4-3, 

 4-4, or 5-4; fur soft. 



9. FAMILY. Cavies (Caviidse). Head generally 



large and thick; facial line nearly straight 

 or slightly curved ; eyes large ; upper lip 



c2 



