No. 1626. MAMMALS FROM HASTERN SUMATRA—LYON. 639 
erizzled with buffy. The region about the shoulder, the outer sur- 
face of the upper arm and outer surface of thigh are very faintly 
grizzled with a buffy or ochraceous buffy color. Ordinarily this griz- 
zling is scarcely noticeable, but evident, though sight in amount 
when the specimens are placed in certain fone A still fainter 
erizzling may be brought out with proper lighting along the side 
just above the Faommnsnne underparts. 
Skull and teeth.—These are distinctly larger and heavier than they 
are in Sciurus piceus, but do not differ in essential respects from 
skulls of S. melanops. 
Measurements.—See table, page 640. 
Specimens re emourtcon, all from Pulo Rupat. 
Remarks.—Sciurus nyx appears to be a very well marked member 
of the Scturus prevosti group of squirrels. Although most lke 
Sciurus piceus with regard to general appearances, its large size, red 
feet, and faint grizzling about the shoulders, thighs, and sides (lack- 
ing in S. piceus), indicate that it has developed from S. melanops, 
rather than from S. piceus. Another fact giving strength to this 
view is that S. melanops is found on the mainland opposite Pulo 
Rupat, while, so far, S. piceus is not known from there. 
Measurements of squirrels of the Sciurus prevostu group from eastern Sumatra. 
8 SO a) 
BS PS Re hs iS) 5 
so} 2) 5 to o TI 
Nae = ae hci Gey | SS | © 
Name. Locality. BoE Sex and age. e s © z fe Bas |S 
SE os eey eee 
Le} = An io) 
S| Be |e te |e 
Be es is 
| 
‘ mm.|mm.\mm.| mm. | mm. | mm 
S.melanops....| Little Siak, at mouth...| 144175 | Female, adult. 280 | 275 | 67 | 61.1 | 24 37 
1) Ose on |5 ees CORRES eee nen: 144176 |....- GOS eee 263 | 280 | 65 | 59.7] 24.5 | 36.4 
WD Ones ies cle ae: doSeis Snhee eee 144177 | Male, adult....... 265 | 285 } 67 | 60.8 | 23.9 | 35.2 
ID) Oye -t eee Gee CO a a atk Se PE 8 Sh 144178 |....- OSS sos ea sees 275 | 220 | 67 | 60 22.4 | 34.6 
WD OFS es St oe CLO tegen eee 144179 |...-. OO. o56ss500080) Zee |) 244) |) Gr || C083 |) 233 35.8 
DOR ee Little Siak River.....-- 144180 | Female, adult... .} 263 | 275 | 64 | 59.2 | 22.2 | 35 
IDO ibe asellaeeee CO Esg ey ays ee ate 144181 | Male, adult....... 260 | 250 | 63 | 58.6 | 24.1 | 35.5 
DORs Seabees Seeee GORE ee ee eS 144182 | Female, adult 275 | 250 | 67 | 58.6 | 23.8 | 35.7 
IDOE oe See aaloseae CORRE a on eee 144183 |..... CORES Ree Rees 270 | 275 | 64 | 59 2B, '5 |) ats, & 
WW Oke ce Makapan.-.....-: Pests 144184 |___.. Chon aoeen ss 257 | 280 | 66 | 58.9 | 23.8 | 37 
IDXO 6 Re esl eer GOs att eee cae 144185 | Male, adult....... 265 | 270 | 66 | 58.7 | 23.5 | 33.8 
I) Ose cence COR eae eae 144186 Hemale, MOM PW || BIS || VO || GL |) HW || GB onsee 
adult. 
1D) OR e aoe IKeOMIPelee seeker ee eee 144187 |. Male, adult....... 270 | 255 |.65 | 59.4 | 23.8 | 35.7 
1D) Oe eal ne Om sae sean ee Sneye 144188 Female, adult. 268 | 275 | 68 | 59.3 | 25 36.5 
WOS cee Kateman Island........ 123109 |..... (OKO aes eae 265 | 263 57 23.7 | 34.6 
DOR eee E Skee CO ey ae Ns ae ZBI |lssooc ae epee tt eres 260 | 275 58 23.7 | 34.7 
DO See aa Kateman River........- T2311 seed OF ae see 270 | 265 61.4 | 25 36.5 
ID YON ese eee Os ee ceh Reese AEA 123113 ils, adul teeeeeee 255 | 278 56.5 | 22.5 | 33 
IBY ee need ene LORE ee Sa W2BUS oocse Oe eae ates 253 | 267 58.3 | 24.3 | 35.3 
DD) ON eo FS aaa ee Clo R eee Me eet Sete NPB Hossoe GK) cg pea ead & 275 | 290 59.5 | 24 35. 6 
DOs8 eee -a |e COWS eect acts 1251220 peer GOA oe A) || 203 Noa al) BED |) HE 35 
DOs sae ass SHG IRW PBs ocoscscecec 143396 |... -- Oss sss 265 | 280 | 69 | 61 24.2 | 35.8 
ID ORS a Bey ste OREN Saran ae: 143397 | Female, adult... .| 255 | 270 | 67 | 58.7 | 22.7 | 35.5 
1D) Osea eoeye CG 0 er et cee eae ae 143398 | Male, adult....--- 267 | 280 | 68 | 58 23.9 | 36.7 
S. ODS jOGe|| Pb IES BNO LS scoccsnnce 144358" |" Hemale, adult:. -2|2-2.-|22.-.|_..- 58.5 | 23.4 | 34.7 
nialius 
IDO Snes eee Cao pats eae Cee eede 144359 |..... COR eras see 280 | 260 | 65 | 60 24 36 
DD) ON ae Se |Aerees CORE ee 144860 |....- GOtE ee en DNS || YS | CB ocoacadloascodllsccce 
IDO er caesar (OKO) i A oes eae 144361 | Male, adult....... 280 | 200 | 68 | 59.7 | 24 36. 6 
IDOLS oer ole seas COR ae ae ae oe 144362 Female, adult....| 277 | 275 | 66 | 58.7 | 22.8 | 33.2 
ID OM Sasosate baeee COs rer sae as cnuse 144363 | Male, adult....... 2C0 | 270 | 67 | 57.7 | 22.8 | 35.7 
ID OG ses eeeralneae GOR Soe ees se ae oe 10144364 ' Female, adult... .! 270 | 278 | 67 | 57.9 | 28.5 ! 36.2 
“ Collector’s measurements. ’ Type. 
