584 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxii. 



tion, 31.8; greatest length of nasal, 29.6; width of both nasals 

 together, 15; maxillary toothrow (alveoli), 19.3; mandibular toothrow 

 (alveoli), 19.5. 



Specimens examined. — Nine skins with skulls, one odd skull, and one 

 skeleton, all from Aru Ba}^, east coast of Sumatra. 



Reniarl'!^. — Thecurus sumatrsi is a very distinct form of porcupine 

 and apparently bears little resemblance to other described genera or 

 species. Externall}^ it closely resembles a small Acanthion., while 

 cranially it has so many points in common with AtliertiruH that there 

 are almost no characters, aside from rootless molars, by which the 

 two may be genericallj^ separated. In many respects it is an inter- 

 mediate link between Acanthion and Atherurus. 



In 1879 '^ Doctor Giinther described a small porcupine from the 

 island of Paragua, Phiiippi-ne Islands, under the name of Ilystrix 

 pumila. I have seen no specimens of this species nor any figures of 

 it, but the original description and the detailed measurements given 

 lead me to believe that Hystrix pumila is closel}' related to Thecurus 

 swnatrx, and may possibly be a second species of that genus. What- 

 ever the relationship. Doctor Giinther's measurements indicate that 

 Hystrix pumila is a distinctly smaller animal than Thecurus sumatrse. 



Subfainily ^THERTJRIlSrjE. 



The subfamily Atheruriuc^ is distinguished among the Hytricidte in 

 the possession of a rather long external tail, with a well-marked scaly 

 portion between its base and apex, which is terminated b}^ a long tuft 

 of modified hairs or bristles; in not having well-developed quills on 

 the back, but mereh^ stiff grooved spines; in having three sacral 

 vertebra and rooted, brachydont molars. It contains two genera: 

 Atherurus., page 584, and Trichys^ page 588. 



ATHERURUS F. Cuvier. 



1829. Athtrurus F. Cuvier, Diet. Sci. Nat., LIX, p. 483. 

 Type. — Hystrix macroura Lin njeus,. from Malacca.* 

 /Species. ~^{Iu Malayan region) Atherurus macnrurus (Linnaeus), from 

 Malacca; A. syr/omaticus Miller, from Pulo Aor; and A. terutaus., 

 new (page 587) Pulo Terutau. 



Diagyiostic characters. — A small sized porcupine, without quills, 

 with a large scaly tail, each scale subtended by three hairs, and 

 terminated by a tuft of bristles, mostly flattened and alternatel}^ con- 

 tracted and expanded one to five times. (Plate LVII, fig. 3.) Skull 



«Ann. Mag. Nat. Hist., IV, 1879, p. 106. 



t'See Jentink, Notes Leyden Museum, XVI, 1894, p. 207, Lyon, Proc. Biol. Soc. 

 Washington, XIX, December 31, 1906, p. 199, and Thomas, Proc. BioL Soc. Wash- 

 ington, XX, p. 66, June 12, 1907. 



