The tail (H. c.) of the common Bornean Porcupine, Hystrix crassispinis, show- 

 ing the modified quills, enlarged at a, which make the rattling noise. 

 Tail (T. 1.) of 'quill-less Porcupine, Trichys lipurr., showing the scaly covering 



and the fine terminal quills, enlarged at b. 

 Plate VII. 



To fa:e p. 



