584 
PROCEEDINGS OF THE NATIONAL MUSEUM. 
™L. XT X 11, 
tion, 31.8; greatest length of nasal, 29.6; width of both nasals 
together, 15; maxillary tootlirow (alveoli), 19.3; mandibular toothrow 
(alveoli), 19.5. 
Specimens examined. — Nine skins with skulls, one odd skull, and one 
skeleton, all from Aru Bay, east coast of Sumatra. 
Ren i ark#. —■ Tkeeur us Sumatra i s a ve ry d i stin ct f o r m o f po re up i n e 
and apparently bears little resemblance to other described genera or 
species. Externally it closely resembles a small Acantkion , while 
eranially it has so many points in common with Atherurus that there 
are almost no characters, aside from rootless molars, by which the 
two may be generically separated. In many respects it is an inter¬ 
mediate link between Acantkion and Atherurus. 
In 1879“ Doctor Gunther described a small porcupine from the 
island of Paragon, Philippine Islands, under the name of Ilystrix 
pumila . 1 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 Ilystrix. pumila is closely related to Thecurus 
Sumatra? and may possibly be a second species of that genus. What¬ 
ever the relationship, Doctor Gliother’s measurements indicate that 
Ilystrix pumila is a distinctly smaller animal than Thecurus Sumatra, 
Subfkmily 
The subfamily Atherurimc is distinguished among the Hytricid© in 
the possession of a rather long external tail, with a well-marked scaly 
portion between its base and apex, which is terminated by a long tuft 
of modified hairs or bristles; in not having well-developed quills on 
tlie back, but merely stiff grooved spines; in 1 laving three sacral 
vertebm and rooted, braehydont molars. It contains two genera: 
Atherurus, page 584, and Triohys^ page 588. 
ATHERURUS F. Cuvier. 
1829, Athtrurus F. Cuvibk, Diet. Sd. Nat., LIX, p. -183. 
Type.■ — Hystrix macroum Li mucus, from Malacca. 6 
Species. — (In Malayan region) Atherurus maccounts (Linnaeus), from 
Malacca; A. sygomaticus Miller, from Pulo Aor; and A, terutam^ 
new (page 587) Pulo Terutau. 
Diagnostic 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 alternately con¬ 
tracted and expanded one to live times. (Plate LYU, fig. 3.) Skull 
“Ann. Mag, Nat. Hist., IV, 1873, p. IQU. 
b See Jentink, Notes Leyden Museum, XVI, 1894, p. 207, Lyon, Proa Biol. Soc. 
Washington, XIX, December 31, 1900, p, 199, and Thomas. Proa Biol. Soc. Wash¬ 
ington, XX, p. 86, June 12, 1907. 
