Gurbillcs in ihc British Museum. 77 



botli above and below ; the last molar nearly circular in each 

 case. 



Dimensions of the type (an adult feuialc in spirit) : — Head 

 and body 113 millini. ; tail, without iuiirs, 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 ; intcrorbital breadth 5" 7 ; interparietal, 

 length 4, breadth 8'7 ; least distance between posterior por- 

 tions of bulla? 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 

 bullfB 14"5 ; greatest vertical height of brain-case and bulla 

 combined 13'8. 



Ilab. 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 ; 

 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 

 Myoxida3 or smaller Sciuridfe 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. 



Gerhillus 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. Tail slender, thinly hairy, but little 

 pencilled terminally. 



