1. PEEABAtE. 221 



■ Peramelidce as an offshoot of the Basywidce, with no special genetic 

 relationship to the Diprotodonts whatever. 



DifBcult of acceptance as this view may appear, it is probably 

 the only one which will explain the extraordinary combination of 

 characters presented by the Peramelidce, since it seems equally 

 improbable either that the earliest Marsupials could have been 

 syndaetylous, or that the Peramelidce could have been originally 

 Diprotodont, and have independently assumed a Polyprotodont 



•dentition, in defaidt of one or other of which alternatives the view, 

 above put forward must be adopted. 



Synopsis of the Genera. 



I. ExiEENAi ChABACTEHS. 



A. Fore limbs with the second, third, and fourth 



digits large and functional, and the first and 

 fifth present, although small and clawless. 



a. Hallux absent. Ears enormously long. Tail 



crested , 1. Pbragale, p. 221. 



b. Hallux present, though clawless. Ears 



medium or short. Tail not crested 2. Pbbamelbs, p. 227. 



B. Fore limbs with the second and third digits 



only functional, the fourth rudimentary, 

 and the first and fifth entirely absent. 



c. Hallux absent. Ears long. TaU slightly 



crested 3. Chceeopus, p. 250. 



II. Ceanial Chaeaciees. 



A. Skull long and narrow, its length more than 



double its breadth. Lower rim of orbit 



not flattened horizontally. 



a. Bullse very large, double, their posterior 



(mastoid) portion swollen. Muzzle abruptly 



contracted opposite p.^ P."* smaller than 



or barely equal to p.^ 1. Pbhagalb, p. 22L 



h. Bullse variable in size, single, their posterior 

 (mastoid) portion unswollen. Muzzle 

 evenly tapering. P.* larger than p.' .... 2. Pbbamelbs, p. 227. 



B. Skull short and broad, its length less than 



double its breadth. Lower rim of orbit 

 broadly expanded horizontally, 

 c. Bullse small, single. P.* larger than p.^ 



Muzzle contracted opposite p.' 3. CncEEOPrs, p. 260 



1. PERAGALE.* ^ 



Type. 

 Macrotis, Iteid, P. Z. S. 1836, p. 131 (nee Dejeauy Cat. 



Coleopt. 1833) P. lagotis. 



Peragalea, Gray, Grey's Austr., App. ii. p. 401 (1841) . . P. lagotis. 



* Blyth (Cuv. An. K. p. 104, 1840) states that Prof. Owen had separated 

 off "The Philander, Peramefe lagotis," as a genus under the name of Thyla- 



