MARSUPIALS. 375 



marked in the Ursine Dasyure or Devil of the Tasmanian Colonists, 

 the largest existing species of the genus, and the dentition of which 

 is represented in PI. 98, fig. 2. 



In some of the smaller species of the carnivorous group, as 

 the Phascogales, the canines lose their great relative size, and the 

 molar teeth present a surface more cuspidated than sectorial : there 

 is also an increased number of teeth, and as a consequence of 

 their equable development they have fewer and shorter interspaces. 

 Thus the Phascogale penicillata may be said, in Hunter's words 

 to have " a mouth full of teeth," and these are adapted for the 

 capture and mastication of insects and other small and low organized 

 animals. 



The genus Phascogale (PI. 98, fig. 3) is characterized by : 



Incisors — ; canines — : premolars — : molars — : = 46. 



3—3 ' 1— 1 ' ^ 3-3 ' 4—4 



In this dental formula may be discerned a step in the transition 

 from the Dasyures to the Opossums, not only in the increased 

 number of spurious molars, but also in the shape and proportions 

 of the incisors. In the upper jaw the two middle incisors are 

 longer than the rest, and separated from them by a brief interval ; 

 they are more curved and project more forward. The three lateral 

 incisors diminish in size to the outermost. The middle incisors 

 of the lower jaw also exceed the lateral ones in size, and project 

 beyond them but not in the same degree, nor are they separated 

 from them by an interval, as in the upper jaw. The canines are 

 relatively smaller than in the Dasyures. The spurious molars present 

 a similar form, but the third in the lower jaw is smaller and simpler 

 than the two preceding ones. The true molars resemble those of 

 the Dasyures. 



The general character of the dentition of these small predatory 

 Marsupials approximates to the insectivorous type, as will be exem- 

 plified in the Shrew, Hedgehog, &c. among the placental Mammalia, 

 and corresponds with the food and habits of the species which thus 

 lead from the predaceous or Sarcophagous to the Entomophagous 

 tribes. 



The interval is further diminished by a lost Marsupial genus 



