638 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXIV. 
Specimens examined.—Six skins with skulls and one skull without 
skin. 
Remarks.—Although the Penjalei prevostii squirrel differs from 
Sciurus melanops of the mainland in apparently but a single char- 
acter, the darker shoulders, yet this character is easily seen and per- 
fectly constant. Doctor Abbott recognized them as distinct in the 
field, remarking “ there is a new Scturus melanops with rufous shoul- 
ders from Pulo Penjalei.” “None of the six skins show any tendency 
toward the light shoulders of S. melanops, and only one out of the 
large series of S. melanops approaches the dark shoulders of the in- 
sular subspecies. This specimen is an adult female, Cat. No. 123109, 
from Kateman Island. It is the only intermediate specimen between 
the two forms so far as known. 
SCIURUS PICEUS Peters. 
1866. Sciurus piceus PETERS, Proc. Zool. Soe. London, p. 429. 
1903. Sciurus erebus MILLER, Proc. U. S. Nat. Mus., XX VI, p. 456, February 
3, 1908: 
1905. Sciurus piceus, SCHNEIDER, Zool. Jahrb. Syst., XXIII, p. 109. 
Twelve specimens of this squirrel were taken at Aru Bay. They do 
not differ from the series of skins collected by Doctor Abbott at Tap- 
anuli Bay to which M. Miller applied the name Sciurus erebus. 
While studying material in the Berlin Museum in 1904 Mr. Miller 
made the following notes on Sciurus piceus Peters: 
Type.—Male, in good condition. The locality given on the label and in the 
original description is Tenasserim, but this is doubtless an error. It was re- 
ceived from Professor Strempel of Rostock together with Presbytis potenziani, 
also supposed to be from Tenasserim but now known to occur on the islands off 
the west coast of Sumatra. The squirrel is undoubtedly from Sumatra also, as 
it agrees in every way with S. erebus. No further history of the specimens can 
be found in the Museum records. There is no indication of a pale lateral stripe 
(present in two NS. pluto). Measurements, head and body, 280; tail vertebra, 
230; hind foot, with and without claws, 62, 59. Skull inside. The collection 
contains a second specimen without locality and a third from Sumatra. 
SCIURUS NYX, new species. 
Type.—Adult female, skin and skull, Cat. No. 143392, U.S.N.M., 
collected on Pulo Rupat, off east coast of Sumatra, March 10, 1906, 
by Dr. W. L. Abbott. Original number 4691. 
Diagnostic characters.—A member of the Scturus prevostui group, 
most like Sciurus piceus Peters, but smaller, and with color of the 
underparts extending on the upper surfaces of the feet. 
Color.—Upperparts, sides, tail, and outer sides of thighs, black; 
underparts and upper surfaces of feet including adjoining portions 
of legs, deep ferruginous. At the base of whiskers the black is finely 
