1900.] FOSSIL MAKSUPIAL FBOM TASMANIA. 793 



(22) The massive nature of the femur and the fact that the 

 inner condyle is larger than the outer one, which is the reverse 

 condition of that which is typical of recent marsupials. 



(23) The strong development of the tuberosity at the upper 

 end of the lesser trochanter, and the presence of a tuberosity at 

 the lower end of the ridge which is continued down from the great 

 trochanter. The latter feature is met with in Phascolomys. 



(24) The position of the head of the femur, which is turned 

 considerably inwards. 



(25) The proportionate leDgth of the femur to that of the head. 

 It is longer than in Trichosurus, shorter than in Phalanger, and 

 agrees most nearly with that of Sarcophilus. 



(26) The strong development of the anterior tuberosity in the 

 tibia. This is more strongly developed than in Phalangeridae 

 and Dasyurus, but not so strongly as in Phascolarctos. 



(27) The distal head of the fibula is somewhat less in size than 

 that of the tibia. 



(28) The upward extension of the olecranon portion of the 

 fibula is considerable and most resembles that found in Phascolomys. 

 The outer condyle of the head articulates with the femur. 



(29) The proportionate length of the fibula and tibia to that of 

 the skull is nearest to that of Pseudochirus. 



(30) The ischium is massive and shows a general resemblance 

 in form to that of Trichosurus. 



(31) The acetabular region is most similar to that of Phascolomys, 

 the lower part only of the distal acetabular border overhangs the 

 synovial cavity in the region of the cotyloid notch. The notch is 

 fairly deep, and the whole acetabular region resembles most nearly 

 that of Phascolomys. 



(32) The ilium is unlike that of any recent marsupial. It has 

 the trihedral form of Macropus or Dendrolagus, but combined with 

 this the distal expansion characteristic of other forms, such as the 

 Phalangeridae, from which, however, it differs markedly in essential 

 structure. 



(33) The great size and straightness of the marsupial bones, 

 which have two articulating surfaces as in Phascolomys. 



(34) The sacrum consists of three fused vertebra?. This occurs 

 in Dasyurus viverrinus. 



(35) The structure of the axis, in which the transverse process 

 runs out almost at right angles to the body, and the ridge 

 which forms the base of the vertebrarterial canal is flattened out, 

 instead of being narrowed from before backward as in all recent 

 marsupials. 



(36) The transverse processes are large broad plates running 

 out almost horizontally: they are unlike those of any recent 

 marsupial. 



It will be seen from the above that the fossil presents a remarkable 

 combination of characters, some of which serve to distinguish it 

 from recent marsupials, while others serve to ally it on the one 



