36 ZOOLOGY OF THE VOYAGE OF THE SULPHUR. 



Family— HYSTRICIDjE. 



The Quilled Rat. — Ciletomys subspinosus. 



Plate XVIII. Fig. 1 to C. — Skull and Teeth. 



Cheetomys subspinosus, Gray, Proc. Zool. Soc, 1843. List Mam. Brit. Mus. 123. 

 Hystrix subspinosa, Licht., Kuhl, Beitr., 71, Pr. Max. Abbild. 



This animal is easily separated from the other South American prehensile-tailed 

 Porcupines by the slenderness and flexible nature of its spines, and also by the 

 conformation of the grinders and form of the skull, which has now been figured 

 for the first time. Each of the upper grinders consists of a douhly folded plate, 

 with a single plate between them. Each of the lower grinders has two sinuous 

 folds on the inner side, and one rather in front of the middle of the outer side ; 

 the front tooth on each side is rather the narrowest. These teeth are inter- 

 mediate in form between those of the American Porcupines and the Agouties 

 (Dasyproctina.) 



Dasyprocta punctata. 



Plate XV. 



Dasyprocta punctata, Gray, Ann. and Mag. Nat. Hist. 1842. 264. List Mam. Brit. Mus. 123. 



Uniformly grisled with greenish yellow. Hair black, with greenish yellow rings. Hair of 

 the back scarcely elongate, and ringed to the base. Throat yellow. Feet rather 

 blacker. 



lnhab. Tropical America. 



Dasyprocta nigra. 



Plate XVI. 



Dasyprocta nigra, Gray, Ann. and Mag. Nat. Hist. 1842. 265. List Mam. Brit. Mus. 128. 



Black grisled, with white ; shoulder and haunches blacker. Legs black ; throat grey ; belly 

 rather greyer. Hair of the back elongate, flattened, and white at the base. 



Inhab. Tropical America. 



