TBICONODONTID^. 257 



^Peragale lagoti;^ (Reid i). 



Syn. Perameles {Macrotis) lagotis, Eeid 2. 



Of large size, with the crowns of the molars elongated and curved. 

 Hah. Western Australia (recent), and New South Wales (Pleis- 

 tocene). 



42663. Part of the right maxilla, containing the last three true 

 molars ; from a cave in the Wellington Valley, jSTew 

 South Wales. 

 Presented hy the Trustees of the Australian Museum, 1870. 



43884. Hinder part of the right ramus of the mandible ; showing 

 the last two molars ; from the same locality. 



Same history. 



Family TRICONODONTIDJE ^ 



Dentition: — T. ^, C. r, Pm. 7, M. — ^. The lower true molars 

 are without an inner cingulum or cusp, and consist of three subequal 

 secant cusps or cones, of which the first two correspond to the blade 

 of the homologous teeth of the Dasyurince, and the third to the 

 talon of the same ; the upper true molars resemble the lower, and 

 have no inner tubercle ; the premolars are much simpler than the 

 true molars, pm, 4 being taller than m. 1 ; and the lower incisors 

 are in contact. The last premolar was preceded by a milk-tooth ; 

 the cheek-teeth are of large relative size, and the mandibular ramus 

 is deep. The inflection of the angle of the mandible is strongly 

 marked ; and the canines have grooved or double roots. 



The one English genus of the present family appears to be a 

 highly specialized primitive form, of which the lower true molars 

 come nearest to those of Thylacinus, and bear the same relation to 

 the lower molars of Dasyurus as is presented by the inferior car- 

 nassial tooth of Icticyon to that of Canis. The specialization of the 

 dentition of this early form is parallelled by the case of Plagiaidaoo 

 among the Diprotodontia. 



1 Proc. Zool. See. 1836, p. 122 —Perameles. 

 ^ Loc. cit. 



^ The division into famiUes of the Mesozoic members of the Suborder, as 

 well as the serial arrangement of such families, must be regarded as provisional. 



PAET V. 



