316 ON THK AFflNltlKS OF CiENOLKSTES, 



J)i|)rot()(l(iiits : and, in connection therewith, I stated "Cceno- 

 lestes has been omitted, as I consider the evidence which 

 would place it with the Australian Diprotodonts not suflfi- 

 ciently strong, and in any case it is evidently not a near ally 

 of any of the Australian forms." 



Most recent authors seem to have accepted Ccenolestes as 

 a primitive, but true Diprotodont. In October, 1909, 

 however, a paper was published by Miss Pauline H. Dederer, 

 in which she compares Ccenolestes with known Polyprotodonts 

 and Diprotodonts.* She shows that Ccenolestes exhibits 

 many Polyprotodont characters, and only very few Diproto- 

 dont ; and her conclusions may be given in her own words. 

 "Sinclair concluded that Caenolestes is very like the primitive 

 Phalangers, and the two families are probably related, not 

 convergent ; that, while the fossil Csenolestidce are too special- 

 ised in tooth-structure to be the direct ancestors of the 

 Phalangers, yet there is probably a common ancestry. Later, 

 he gave weight to the possibility of convergence to account 

 for the resemblance in tooth-structure. This latter view 

 would seem to be more in accord with the facts known about 

 Caenolestes, for excepting tooth-structure, there appears to 

 be no other important character which links it with the 

 Diprotodonts, and there are several, as given above, which 

 link it with the Polyprotodonts. While there is undeniably 

 a series of forms connecting Caenolestes with the Diproto- 

 donts in tooth-structure, yet Caenolestes itself is so generalised 

 in this respect, that we may perhaps, in the absence of other 

 corroborating characters, question its inclusion within this 

 group. Possibly it may be found to be an offshoot from the 

 Polyprotodonts, as it appears structurally to be more general- 

 ised than any Diprotodont, and, therefore, it might well 

 occupy a separate suborder, as Thomas suggested — the Pauci- 

 ttibcrculata of Anicghino." Thomas liad siiggcstcd tliat a 

 further knowledge of the soft parts, skeleton, and milk- 



* American Naturalist, xliii., 614. 



