1 



MtJRID.K. 



MUIUD^E. 



are holding U mall enough to be held between their finger* and the 

 tubercle at the baee of the thumb. 



Thi* specie* appear* to be known in Cuba by the name of Utia, and 

 M. Desmarert think* that it U the animal described by Bomare, 

 Oviedo, and other*, more than 300 yean since. According to liomare, 

 the Uliaa U a peoie* of rabbit of the ite of a rat, which inhabit* 

 the Weet Indie*, and U hunted at night by the light of a luminous 

 insect, named Aeadia (propably Stater *octil*ciu), of which M. Fouraier 

 brought Urge quantities from Cuba. 



Another specie*, also from Cuba, Capromyi preiieiuilit (Piippig), 

 U also recorded, but Dr. Fisober place* the mark of doubt before it 

 [HTRBICIDJL] 



1'rofeseor Owen has made some observations on the comparative 

 anatomy of Capnmyi In the ' ZooL Proc.' for 1832 and 1835. 



IViorttu is a genus of the family Muritlti, including the Common 

 Hamster. [CuccTua,] 



Jumping Mice. 



The race of Jerboas, or Dipotlida, appears to be ordained by nature 

 for living upon desert and sandy plains. 



Schreber, and be was followed by Gmelin and others, appears to 

 have been the first who characterised the genus Dipiu. 



Dr. Gray (' Annals of Philosophy,' 1826) makes the Jerbo\d(f the 

 fourth family of the Glint, and thus characterises it : Cutting-teeth 

 two in each jaw ; grinders simple or compound, rooted ; ears moderate ; 

 eyes large, prominent; clavicles dUtinot; fore feet short (used as 

 haiuL)); hind feet very long; tail long, hairy, used in leaping or 

 walking ; fur soft And he thus divides the family : 



t Grinders compound or rootles*. 

 1. Palalina; Pedtttti, Illig. 2. Dipina; Dipta, Schrcb.; Mtrivna, 

 F. Cuv., not Illig. 



ft Grinders simple, roots divided ; legs nearly equal. 

 3. Gerbiitta, Desm. 4. ifyoxina; Myoxut, Gm. 5. Sciurina ; 

 Sciuroptrrtu, F. Cuv. ; Ptcromyt, Cuv. ; Macroxva, F. Cuv. ; Sciurtu, Linn. ; 

 Tamai, Illig. The latter genus very closely allied to Arctomina. 



Mr. Swainson (' Classification of Quadrupeds') observes that the 

 Jerboas (Dipvt) are remarkable for possessing the longest hind legs of 

 any quadrupeds yet discovered, while the fore legs are dispropor- 

 tionally short ; this structure ho remarks is seen also in the Kangaroos, 

 which seem to be represented in miniature by these little animals, 

 which, " like their pouched prototypes, use the tore feet only as organs 

 of rent upon.the ground ; for if they are frightened or wish to proceed 

 at a quick pace, they stand upon the hind legs only, and take prodi- 

 gious leaps." That the tail is necessary for the efficient performance 

 of these feat*, is proved by the fact that individuals deprived of their 

 tails were unable to assume the erect position or to leap at all. The 

 fore feet are employed in conveying food to the mouth, and seem to 

 be of little or no use as organ* of progression. Those that we have 

 seen alive seemed to use their posterior extremities only as organs ol 

 locomotion, and appeared to walk on the toes of those extremities. 

 They are very bird-like in some of their movement*, and there is some- 

 thing in their general appearance that would lead on imaginative mind 

 to the fancy that they were birds suddenly transformed to quadrupeds 

 and were hardly reconciled to the change. Parts of their internal 

 structure, in the skeleton particularly, are bird-like. 



Mr. Swainson says, "The best-known species U the Gerbo, or 

 Egyptian Jerboa (I)ipu* Sayiita), in which country it U very common. 

 It lives in huge societies, and constructs burrows under ground : it is 

 shy and timid, nor can it be kept in confinement any considerable 

 time. Of four typical species already known, three inhabit the sand} 

 deserts in the heart of Asia, and the shores of the Caspian ; the real 

 have been separated as a sub-genus, under the name of Gerbil (O'er 

 lilliu) ; but their distinctions are so very slight that we have not 

 adopted the name. The genus Pedeta, represented by the Cape 

 Jerboa, clearly belong* to the same group. America, which has no 

 Jerboa*, nevertheless presents us with their prototypes in the Jumping 

 Mice of Canada (MtrioHt,, Illig.)." 



The Jerboa* have, in truth, presented considerable difficulties to 

 xoologista, and the distinction of the species is often not clearly mode 

 out Sonnini was one of the first who endeavoured to dissipate the 

 confusion which prevailed on the subject He come* to the conclusion 

 that there exist* but one variety of them in Egypt, where they are 

 multiplied without end. "In fact," says M. Sonnini, "among al 

 thoae which I have observed at different times and in different place.' 

 I never remarked the least dissimilitude of either form or colour.' 

 His paper, M. Berthout van Berchem's letter on the true nomencla 

 ture of the Gerboiae, and M. Sonnini's reply to the same, will be fount 

 in the ' Travels' of the latter in Upper and Lower Kgypt That them 

 Jerboa* were known to the ancient* is evident Herodotus (iv. 192 

 allude* to them a* inhabiting Africa. Aristotle (' Hint Anim.,' vi. 37 

 peaks of them a* tho*c Kgyptian Itats which walk on two feet, bccaiue 

 the hind feet are great and the fore feet small. They are noticed by 

 ,KUn (xv. 20), who quotes Theophnutus. The description of Theo 

 phrutu* (Fr. xiv.) cannot be mistaken. He says that these rat* 

 have indeed fore feet, but do not walk upon them, and use them as 

 band*. When they flee, he add*, they leap. They an clearly the 



Kyyptii miiret of Pliny, who says 'bipedti ambulant' (x. 65), and 

 'ennant give* an engraving of a gold coin with the plant SiljAium and 

 one of these animal* represented on it, and says that these symbols 

 were used to denote the country of Cyrene, where both were found. 



One of the best monographs of the genus J>ij>ut is that of M. I.ich- 

 enstein : the species he gives are numerous, and it may be doubted 

 whether aorne of them are not varieties. A very elaborate memoir 

 on the Jerboas and GerbilUs, by F. Cuvier, was read before the 

 Zoological Society of London in 1838, and is published, with beautiful 

 illustrations, in the Transactions ' of that Society (voL iL). 



I 



Skull and Teeth of Dipia hirtlfei. F. Cuvier. 



a, ikull, profile ; &, same, seen from above ; e, same, seen from btlow; d, t, 

 teeth of same. 



6 



Skull anil Teeth of Aluttaya. 



IT, H, cranium, one-third larger than natural lze ; r, J, teeth of the samp, live 

 time* larger than nature. 



