498 



TREE rORCUPINES 



in both families we have long -tailed and short -tailed forms. 

 Cercolabes corresponds to Atherura or Tricliys, and Erciliizon 

 to Hystrix. 



The ffenus Eretliizon, the " Urson " of Canada, has a short, 

 stumpy tail. Its spines are almost hidden by enveloping hair. 

 The fore-feet have four, the hind-feet five toes. The short tail of 

 this creature is remarkable when we reflect upon its climbing 

 habits. It appears, however, to be a weapon with which it 

 strikes sideways at the enemy. 



Of the Neotropical genus Cercolabes (sometimes called S})liin- 

 giirus, Synetheres, or Coendou) there are some eight or nine 

 species, all found in Central and South America. The animal is 



Fig. 244. — Brazilian Tree Porcupine. Sphlnfjurus jjrehensilis. x J. 



arboreal, and has in correspondence with that habit a prehensile 

 tail. The spines are not so stout as in the Ground Porcupines, 

 and are often coloured yellowish or reddish. In correlation with 

 its tree-frequenting habits the bones of Cercolabes show certain 

 differences from those of the Ground Porcupines. The scapula is 

 broader and rounder in front than is that of Hystrix; the 

 phalanges of the thumb (which is rudimentary) are fused 

 together as in the Canadian Eretliizon ; but those of the very 

 small hallux are also fused, whereas in Eretliizon, as in Hystrix, 

 they are separate. In one species, C insidiosus, Sir W. Flower 

 states that there are as many as seventeen dorsal vertebrae 

 and thirty-six caudals. The tail is thus very long. In C. 

 villosus there are fifteen dorsals and twenty-seven caudals ; eight 

 ribs reach the sternum, which is composed of seven pieces, the 



