MAY, 1921. AMERICAN MARSUPIAL, C^ENOLESTES OSGOOD. n 



Gidley (1915), in a short footnote, expresses an opinion similar to 

 that of Broom, saying: "The Casnolestidae have been placed in this 

 great group [Diprotodontia] apparently on the diprotodont-like de- 

 velopment of the lower jaw. However, this may be an entirely in- 

 dependently acquired character. This family more probably belongs 

 with the Polyprotodonts." 



With the exception of casual references in general works, nothing else 

 of importance has appeared in reference to the systematic or phylo- 

 genetic position of Canolestes. The occurrence of the animal in several 

 different localities has been recorded (Osgood, 1912; Stone, 1914) and 

 the number of species has been increased at least nominally to three, one 

 of which has been made the type of a second genus, Orolestes (Thomas, 

 1917), which, as described, seems only slightly different from the original 

 form. 1 



Reviewing the foregoing it is seen that, within two decades and upon 

 a knowledge of its cranial and external characters only, Coenokstes has 

 been placed in three different suborders and that various competent 

 authors have disagreed as to its proper position. Thomas, Ameghino 

 and Scott frankly classify it with Australian diprotodonts; Sinclair 

 inclines to do the same; Bensley, Miss Dederer and Gregory believe its 

 diprotodont characters are convergent and place it in a suborder of its 

 own; while Broom and Gidley would rank it merely as an aberrant 

 polyprotodont. Beginning with that of the period prior to the dis- 

 covery of Canolestes, the following are the various classifications of 

 marsupials concerned in its history, wholly extinct groups being in- 

 dicated by a dagger: 



THOMAS 1888. 



Order MARSUPIALIA 



Suborder Diprotodontia 



Family i. Macropodidae 



2. Phalangeridae 



3. Phascolomyidae 



Suborder Polyprotodontia 



Family r. Peramelidae 



2. Dasyuridae 



3 . Didelphyidae 



1 At the time of writing, the privilege of examining specimens of Orolestes is denied 

 me. 



