Dirvus. bic: 
auditory bullee usually greatly developed; metatarsal bones elongated, 
often fused into a cannon bone; form gracile; front portion of body and 
fore-limbs very small; hind limbs long and strong, with from three to 
five digits; tail long, hairy. Three sub-families” (AZston On the Order 
Guires, ‘P. Z. S.’ 1876). The three sub-families are Zapodide,* 
Dipodine and FPedetine, but we have only to deal with the second. 
GENUS DIPUS—THE FERBOAS. 
Hind feet with three digits; tail cylindrical and tufted; incisors 
grooved ; premolars absent, or, if found, then in the upper jaw and rudi- 
mentary; skull with very broad occipital region; greatly developed 
auditory bullee ; the cervical vertebree are more or less anchylosed, and 
the metatarsals are united. ‘They are not found in the plains of India, 
though one species inhabits Yarkand, and two more are found in 
Eastern Persia. 
No. 400. DIPUS LAGOPUS. 
The Yarkand Jerboa. 
Hasitat.—Koshtak, south of Yarkand; Yarkand ; and Yangihissar. 
—Blanford. 
Description.—“ Colour above light sandy brown, slightly washed 
with dusky, below pure white ; a white band across the outside of the 
thigh ; tail pale brown above, whitish below, with a tuft of longer hair, 
altogether about 23 inches long; at the end the terminal portion pure 
white, the proximal portion black or dark-brown on the upper part and 
sides, but brown or white beneath the tail. The fur is very soft and 
rather long, 0°6 to o°8 inch in the middle of the back; on the upper 
parts it is ashy grey at the base and for the greater parts of its length, 
pale sandy brown near the end; the extreme tip dusky brown; on the 
lower parts it is white throughout; ears about half the length of the 
head, oval, naked inside, thinly clothed with short brown hair outside ; 
face sandy ; the hairs grey at the base ; sides of head whitish ; whiskers 
as usual very long, exceeding three inches; the uppermost brown; the 
longest white, except at the base; the lower entirely white ; the long 
hairs beneath the,hind feet all white, as are the feet throughout.”— 
Blanford, ‘Sc. Res. of Sec. Yarkand Mission,’ pp. 58, 59. 
* Formerly Jaculine. 
