874 Mb, oldField laoMAs. on a new [I)ec. 17, 



Diprotodonts, its length in front o£ the jaw-bone exceeding that of 

 the three anterior molars. Succeeding it, just as in the same Aus- 

 tralian group, are four minute unicuspid teeth, which it seems best 

 for the present tentatively to call two premolars, one canine and a 

 pi-emolar. Any other determination would involve the presence of 

 four incisors or four premolars, each equally unlikely. Then come 

 two narrow, pointed, two-rooted teeth, obviously premolars, the 

 posterior slightly longer than the anterior, and, as in the upper jaw, 

 just overtopping the molars. Molars low-crowned, more or less oval 

 in section, and each with two roots. Their pattern is difficult to 

 make out accurately, owing to a doubt as to how far they are affected 

 by wear. The anterior ones each seem to have two curved or angular 

 crests, whose concavity is directed inwards, somewhat similar to 

 those of the Indian Ehinoceros, but they are far less distinct ; the 

 posterior is larger and more open as compared with the much smaller 

 and less open anterior one, and they are very probably produced 

 in a wholly different way ; the anterior crest is decidedly higher 

 than the posterior. The last molar is much smaller than the 

 other, and has two pointed cusps corresponding to the ci'ests of 

 the other teeth : both rather inwards of the middle line. 



The following are some dimensions of the specimen described, 

 the type of C. obscurus : — 



Head and body 151 mm. ; tail 144 ; hind foot without claws 23 ; 

 heel to end of hallux 14-2 ; hallux 3-2 ; ear 12 x 11"5. 



Skull — basal length 33-6 ; greatest length in middle line 36 ; 

 greatest breadth 18; nasals, length 17*8, greatest breadth, approxi- 

 mately, 5-4 ; intertemporal breadth 7 ; breadth of brain-case 

 12"8 ; height of brain-case above basilar suture 9 ; palate, length 

 from gnathion 20-6, breadth outside m^ 8-3, inside ^ 5; anterior 

 palatine foramina 6-2; length of palatal vacuities 7"2; combined 

 length of ms.'-" 5-1, Lower jaw, length from condyle, bone only, 

 23-8, including [i 28-5 ; height of coronoid above angle 10 ; 

 vertical thickness of ramus below m' 3 ; length of i~ beyond bone 

 above 6 ; length of lower molar series 6*9. 



We may now pass from these necessary, but dry and unin- 

 teresting details to the important question as to what Marsupial 

 Ccenolestes is most nearly allied to, for Marsupial it is in every 

 character. With regard to living members of the order, the 

 answer can only be that it is allied, at least closely, to none, but that, 

 so far as it has any existing relations, these are distinctly the 

 Australian rather than the American Marsupials. Eor it is clearly 

 a Diprotodont, as not only does it possess the characteristic 

 development of the lower incisors, but even the molars resemble 

 most closely in structure those of certain members of the family 

 Fhalangeridce, while being wholly unlike those of the typical 

 Polyprotodonts. 



Trom all of the existing Diprotodonts, however, apart from its 

 habitat and numerous detailed differences, Ccenolestes is at once 

 distinguished by its not being syndactylous, a character which is 



