SCIURIDAX—SPERMOPHILUS EMPETRA. 845 
. 
society is generally observed sitting erect on the summit of the hillock, whilst 
the others are feeding in the neighborhood. Upon the approach of danger, 
he gives the alarm, and they instantly betake themselves to their holes, remain- 
ing chattering, however, at the entrances until the advance of the enemy 
obliges them to retire to the bottom.”* It extends southward in the interior 
at least to Fort Yukon. Mr. B. R. Ross, in notes sent with specimens 
(labelled “Arctomys kennicottiz”) to the Smithsonian Institution, says it is 
“numerous in the Barren Grounds, as well as along the Arctic Coast, and by 
no means scarce along the Anderson and Lockhart Rivers; also numerous 
below Good Hope, on the Mackenzie; they burrow in considerable numbers, 
one always acting as sentinel while the others feed and otherwise disport 
themselves”. Most of the specimens in the collection are from the vicinity 
of Forts Anderson and Yukon. It also extends considerably to the south- 
westward along the Yukon River; and Dr. Richardson also gives it as rang- 
ing on the Pacific coast from British Columbia (formerly New Caledonia) to 
the Icy Cape It also occurs on the Asiatic side of Behring’s Strait, and 
also, according to authors, in Kamtschatka. To the southwestward it passes 
into the smaller, darker, and longer-tailed var. erythrogluteus, which extends 
southward to the forty-ninth parallel. 
TABLE XCI.—Measurements of six skulls of SPERMOPHILUS EMPETRA var, EMPETRA. 
A S S is | 
ei | eS IESG 2 3 
. | = = ae r| 
ro =| 2s oa Boy |Pesincaill oss 
3 ) 2 = Fa| $s |S o 
a 4a | 2 |= |e) 2 |S w/a 
: Sl ecieel ay ey aS| Ba] © |e e| : 5 
>] ' a += =) ~ ° SO e a a = 
s wiles 3s 15 = | -3/2 = a 
3 m g a a) ee iced Sg - |o sl to ‘eo 
g Locality. a E 2 E Bae SeGni tee teeters free a 3 
5 a 3 2 a c oe |S So & $ | 4 
A 2 e $ o o CoN a a |orRle ap 5 < 
} te E 2 | a Ero Skis -| 8 Sis ee 5 
g a » 2 ° 2 6 Ag| a x Ao ler as/| & & 
oo 2 Da 3° a a 2 wm Elem § = I a = = 
g alslaielals |Sélszl & |eslsa) & | 8 
4 | s/s 3 FI BS |) ceases eeacea| esa ence | bene, | ee Ps 
a =) B = a s |akiad) a |aslas! 6 5 
o A o a A A A i=) i.) i=) i=) i=) H | 
6246 | 0.83 | 0.28 | 0.44 | 0.74 | 1.29 | 0.33 | 0.25 | 0.59 | 1.60 | 0. 64 
6247 0,76 | 0.26 | 0.42 | 0.70 | 1.31 | 0.35 | 0.25 | 0.55 | 1.51 | 0.65 
6245 0.75 | 0.25 | 0.40 | 0.65 | 1.23 | 0.31 | 0.23 | 0.53 | 1.37 | 0.65 
6248 0.75 | 0.25 | 0.36 | 0.62 | 1.23 | 0.32 | 0.26 | 0.55 | 1.50 | 0.63 
6251 5 E 0.75 | 0.25 | 0.40 | 0.62 | 1.20 }...... 0. 22 | 0.54 | 1.46 | 0.65 
4805 | Fort Good Hope . Ns 0,85 | 0.25 | 0.36 | 0.70 | 1.35 | 0.31 | 0.24 | 0.58 | 1.53 | 0.67 
*auna Boreali-Americana, vol, i, p. 158, 1829. 
t Zodl. Beechey’s Voy. Mam. p. 7, 1839. 
