Gerbilles ca the British Museum. We 
both above and below ; the last molar nearly circular in each 
case. 
Dimensions of the type (an adult female in spirit) :—Head 
and body 113 millim. ; tail, without hairs, 152; hind foot 31 ; 
ear (above crown) 15. 
Skull: basal length 31; greatest length, from tip of nasals 
to occiput, 37; greatest breadth, at anterior edge of auditory 
meatus, 19°6; zygomatic breadth 19°2 ; nasals, length 14:5, 
greatest breadth 3°4; interorbital breadth 5:7 ; interparietal, 
length 4, breadth 8°7; least distance between posterior por- 
tions of bullee across occiput 7°9; length of anterior zygoma- 
root 5°5; palate, length 19°4, diastema 9°5, palatal foramina 
6°8; length of upper molar series 5; greatest diameter of 
bulle 14°5; greatest vertical height of brain-case and bulla 
combined 13°8. 
Hab. Unknown. 
The type specimen of this species has been in the Museum 
at least since 1837, and probably considerably longer, for 
about that date it was entered by Dr. Gray in the first manu- ‘ 
script list of the then Museum collection of rodents in spirit 5 
and even then its history seems to have been already for- 
gotten, as it is merely entered as “22. a. Sciurus,” the 
localities, donors, &c. being in other cases entered in the same 
list. It is noteworthy that so distinct a species has never 
turned up since. 
G. calurus is a most striking and remarkable species, 
differing from every other member of the group by its evenly 
bushy tail, which more resembles that of one of the larger 
Myoxide or smaller Sciuridee than that of a Gerbille. This 
last resemblance is curiously exemplified by Dr. Gray’s entry 
of the specimen already referred to. In addition only some 
three or four other species, and these quite small ones, half 
the size of G. calurus, have six posterior foot-pads. They 
are all African, and there is every probability that G*. calurus 
also comes from that continent, as the Asiatic species all 
have palms and soles of quite a different character. 
Gerbillus gracilis, sp. n. 
Size rather small, form slender and graceful. Ears large, 
rounded, laid forward they reach to the anterior canthus of 
the eye. Palms and soles as in G, indicus, leucogaster, afer, 
and others, viz. naked, the palms granulated and with five 
pads, the soles smooth posteriorly, granulated anteriorly, and 
with four small pads. ‘T’ail slender, thinly hairy, but little 
pencilled terminally. 
