436 
VERTEBEATA. 
in India; tlie EctTptian Gerbil, G. uEgyptiacus, the Dixms Gerhillus of Olivier; the Gerbil 
OF THE Pyramids, G. pyramiLkim, both found in Egypt; Burton's Gerbil, G. Burtoni, of 
Eastern Africa; the Short-tailed Gerbil, G. brevicaudatus, and the African Gerbil, G. 
afer of Gray, both of Southern Africa; the G.pygargiis, of Upper Egypt and Senegal; Shaw's 
Gerbil, G. Shawii, of Northern Africa. There are other species, not fully described, in Alge- 
ria, bordering on the Desert of Sahara. 
Genus PSAMMONYS : Fsammonys of Rappel. — This comprises a single species, the P. obesus, 
the size of a common rat, resembling both the field-rat and the gerbil, and found in India and 
Arabia. 
SMINTHUS LOEIGER. 
Genus SMINTHUS : Sminthus. — This contains the S. longer — described byNordmann — two 
and a half inches long, with a tail of nearly equal length. It is of a grayish-brown, with a black 
band running along the back. It is dormant in winter. The Mus beteUnus of Pallas is referred 
to the same genus by Nilsson. 
CAFFRAEIAN OTOMXS. 
Genus MERIONES : Meriones. — ^Under this terra, used by Illiger as synonymous with Ger- 
hillus, and which is equivalent to the Jaculus of Wagler, is included but a single species, the 
Labrador or Canada JuMPiNCr-MousE, which is sometimes called the Canada Jerboa ; it is the 
GerUlle du Canada of F. Cuvier; the M. Labradorius of Richardson ; the M. Americanus of De 
