RODENTIA. 619 



extends from Canada to Mexico. The Rabbit is also a native 

 of temperate regions, but appears to thrive, to a more than 

 average extent, in Australia. 



In the Calling Hares or Pikas (Lagomys), the legs do not 

 differ much in size, there is no visible tail, and the clavicles 

 are nearly complete. They are found in Russia, Siberia, and 

 North America. 



Fam. 2. CavidcE. As examples of this family maybe taken 

 the Capybara (Hydrochcerus capybara) and the Guinea-pig 

 (Ancemd). In this family the body is covered with hair, 

 without spines, and the tail is rudimentary. The Capybara is 

 the largest of living Rodents, attaining a length of three or 

 four feet. It is a South American form, leading a semi-aquatic 

 life, to which end the feet are incompletely webbed. It is a 

 harmless stupid animal, and is not unlike a small pig in appear- 

 ance. The Cavia apercea is likewise a South American animal, 

 and is believed to be the parent stock of the Guinea-pigs so 

 often kept as domestic pets in Europe. To the same group 

 as the Capybara belong the Agoutis (Dasyprocta) and the Pacas 

 (Cailogenys\ all of which have eight rootless molars in each 

 jaw, whilst the two former have four toes to the fore-feet, and 

 three toes on the hind-feet. The various species of Agouti are 

 found in South America and the West Indies, whilst the Pacas 

 are exclusively South American. In this family, also, are 

 usually placed the Chinchillas (Chinchilla} of Chili and Peru. 



Fam. 3. Hystricidce. In this family are the well-known Por- 

 cupines, distinguished from the other Rodents by the fact that 

 the body is covered with long spines or " quills," mixed with 

 bristly hairs. They have four molars on each side of each jaw, 

 and they possess imperfect clavicles. 



The true Porcupines (Hystrioc] have non-prehensile tails, 

 which are mostly furnished with long hollow spines, but some- 

 times with scales and bristles. They are found in both the 

 Old and New World, but the American species differ in several 

 respects from those of the eastern hemisphere. They are mostly 

 inhabitants of hot climates, with the exception of the common 

 Porcupine (H. cristata), which occurs in southern Europe and 

 in the north of Africa. In the genus Atherura of Asia and the 

 Indian Archipelago, the tail is terminated by a bundle of flat- 

 tened horny strips. In the genus Erethizon, represented by 

 the Canada Porcupine (E. dorsatum) of North America, the 

 quills are short, and are half hidden in the hair. 



The nearly-allied genus Cercolabes is South American, and it 

 is distinguished from the preceding by the possession of a 

 long prehensile tail. In fact, Cercolabes, like so many of the 



