294 MAKSUPIALIA. 



47751. The greater part of the left ramus of the mandible, containing 

 (Fig.) three true molars; from the Middle Purbeck group of 

 Durdlestone Bay, Swanage, Dorsetshire. This specimen 

 is the type, and is figured by Owen in his ' Mesozoic Mam- 

 malia ' (Mon. Pal. Soc.), pi. i. fig. 39. 



Beckles Collection. Purchased, 1876. 



47799. Fragment of a maxillary ramus with the last two true molars, 

 perhaps belonging to this species ; from the same locality. 



Same history. 



Genus PERALESTES, Owen '. 



This genus was founded upon a maxilla, of which the true molars 

 (6 in number) agree so closely in structure with those of Chryso- 

 chloris that there is every probability that the specimen belongs to 

 Spalacotherium tricuspidens. The fourth upper premolar is of a 

 Dasyurine type. 



Owen regarded Peralestes as allied to Amblotherium, and associated 

 with it a mandible which, as mentioned above (p. 275), cannot 

 apparently be distinguished from A. mustelula. 



Peralestes longirostris, Owen 2 . 

 Hob. Europe (England). 



47740. Part of the right maxilla, showing pm. 4 and the six true 



(Fig.) molars ; from the Middle Purbeck group of Durdlestone 



Bay, Swanage, Dorsetshire. This specimen is the type, 



and is figured by Owen in his ' Mesozoic Mammalia ' (Mon. 



Pal. Soc.), pi. ii. fig. 3. 



Beckles Collection. Purchased, 1876. 



SPECIMENS OF WHICH THE FAMILIES AEE UNDETERMINED. 



A. From the Middle Purleclf group of Durdlestone Bay, Swanage, 



Dorsetshire. 



All the following specimens belong to the Beckles Collection. 

 Purchased, 1876. 



47737. Fragment of a left mandibular ramus containing two (? pre- 

 (Fig.) molar) teeth. Figured by Owen in his ' Mesozoic Mam- 

 malia ' (Mon. Pal. Soc.), pi. i. fig. 41, and provisionally 

 named Phascolestes (?) dulius. 



1 Mesozoic Mammalia (Mon. Pal. SOP.), j,. 33 (1871). 2 loo. cit. 



