RODENT[A. 131 



probably as many species.* One or the other is found frorn Bar- 

 bary to the E-istern Ocean, and as far as the north of India. 



Helamys, F. Cuv. — Pedetes, IlUg.-\ 



We separate from the other Jerboas, and the whole of the genus Rats, 

 the Jumping Hares, which, like the Jerboas, have a large head, and great 

 eyes, a long tail, and the anterior part of the body extremely small in 

 comparison to the posterior, although the disproportion is much less than 

 in the true Jerboas. The peculiar characters of the Ilelamys are four 

 grinders everywhere, each one composed of two lamina? ; five toes to tlie 

 fore feet, armed with long and pointed nails, and four to their great hind 

 ones, all separate, even to the bones of the i^etatarsus, and terminated by 

 large nails, almost resembling hoofs. This number of toes is the inverse 

 of that most common among the rats. Their inferior incisors are trun- 

 cated, and not pointed like those of the true Jerboas, and of the greater 

 part of the animals comprised under the genus of rats. One species only 

 is known, the 



H. caffer.; Museaffer., Pall. ; Dipus caffer., Gm., BufF. Supp.VI. 

 xli, and better, Fred. Cuv. Mammif. It is the size of a hare, of a 

 light fawn colour, and has a long tufted tail, with a black tip. In- 

 habits deep burrows at the Cape of Good Hope. 



Spalax, GuldcHstedt. 



The Rat-Moles have also been very properly separated from the Rats, 

 although their grinders are three in number, and tuberculous, as in the 

 true rats, and the hamsters, and are merely a little less unequal. Their 

 incisors, however, are too large to be covered by the lips, and the extre- 

 mity of the lower ones is in a sharp edge, and not pointed. Their legs 

 are very short; each foot has five short toes, and as many fiat and slender 

 nails. Their tail is very short, or rather there is none ; the same ob- 

 servation applies to their external ear. They live under ground like the 

 moles, raising up the earth like them, although provided with much in- 

 ferior means for dividing it ; but they subsist on roots only. 



S. ti/phus; M. typhus, Pall. Glir. pi. viii, Schreb. 206. (The 

 Zemni Slepez or Blind Rat-Mole). A singular animal, whose as- 

 pect is utterly misshapen by its bulky head, which is angular on its 

 sides, by its short feet, by the entire absence of a tail; but, above 

 all, by its possessing no eye which can be seen externally, it having 

 merely under the skin a small black point, which would seem or- 

 ganized for an eye, without being able however to minister to vision, 

 inasmuch as the skin passes over it without either opening or be- 

 coming thinner, and not having in this spot less hair than any other 

 part. It is rather larger than our rat ; its fur is smooth, and of an 

 ash colour, bordering on a red. This is the animal, in the opinion 

 of Olivier, to which the ancients alluded when they spoke of the 

 mole as being perfectly blind. 



* Pallas has latterly distinguished the small Alactagas by the name of Dip. acontion. 

 I Pedetes, Jumper, Helamyx, Jumpiiig-lxat. 

 k2 



