On a new Genus of Mammalia. 31 



of the toes, which, Hke that of the sloth, pangolin, and 

 mvrmecophagi, is cleft at the free extreniity. 



It needs excite no surprise that I should here employ the 

 last character among the number of those which may serve 

 tor the determination of the genera, if we recollect the 

 result to which my colleague, Dumeril, was conducted by 

 his learned researches in regard to the different configura- 

 tions of the unguical bone. It is indeed natural that this 

 small bone which terminates the fingers, and serves as a 

 mould to the corneous matter with which they are covered, 

 should contribute more than all the other parts of the hand 

 to those dftemiinations of animals which are founded on 

 touching. 



The feet of the perameles, remarka!)lc by the conforma- 

 tion of the last phalangium, are distinguished also by the 

 combination and numerical arrangement of the fingers iit 

 the fore feet : the three middle fingers only can rest on the 

 ground while the animal is walking ; those on the sides are 

 so short that thcv exist only in rudiments, and they are 

 perceived behind the feet only, under the form of a spur. 



The hind feet have a great analogy to those of the kan- 

 guroo : the fourth finger is the longest and the largest ; tha. 

 second and third are united and enveloped under common 

 integuments. They arc distinguished, however, by their 

 claws, which are free ; these two fingers are besides shorter 

 and slenderer than the last or the fifth. The character by 

 which the feet of the perameles differ however from those 

 of the kanguroos, is the presence of a thumb, which 

 really exists though it is very short. It is needless, no 

 doubt, to add that this thumb has no nail, since it is ond 

 of the distinguishing attributes of all the marsupials. 



The organs of mastication appear also in the new family 

 of the perameles, in an order which has never yet presented 

 itsdf to observation. The canine and molar teeth have 

 indeed a rcseniblancc, in regard to their number, fonn, and 

 airaijgcment, to those of the daysiu-es and the didelpha ; 

 that is to say, the perameles have four long canine tecih and 

 twenty-eight molar. But the case is not the same in re- 

 gard to the incisors ; for if there be ten in the upper jaw, 

 as in the didelpha, the order is difTcrent. The last incisor 

 on each side is very much separated both from those of 

 the same kuul liefore and from the canine tooth behind ; 

 and this incisor has besides the form, and discharges the 

 office, of a second canine tooth : it is implanted however in 

 the intcrma.\illary or incisive bene : moreover in the lower 

 jaw there art only $i.\ teeth; a curious anomaly, ■iince this 



