522 General Notes. [June, 



nus is herbivorous, Thylacoleo is so also. Professor Flower re- 

 fers to the reduction of the molars in Thylacoleo as slightly com- 

 plicating the problem, and concludes that the food of that animal 

 may have been fruit or juicy roots, or even meat. It is difficult 

 to imagine what kind of vegetable food could have been appro- 

 priated by such a dentition as that of Ptilodus and Thylacoleo. 

 The sharp thin, serrate, or smooth edges, are adapted for making 

 cuts and dividing food into pieces. That these pieces were 

 swallowed whole, is indicated by the small size and weak structure 

 •of the molar teeth, which are not adapted for crushing or grind- 

 ing. It is not necessary to suppose that the dentition was used 

 on the same kind of food in the large and the small species. In 

 Ptilodus medicevus the diet may have consisted of small eggs, 

 which were picked up by the incisors and cut by the fourth pre- 

 molar. In Thylacoleo it might have been larger eggs, as those of 

 the crocodiles, or perhaps carrion, or even the weaker living ani- 

 mals. The objection to the supposition that the food consisted 

 of vegetables, is found in the necessity of swallowing the pieces 

 without mastication. In case it could have been of a vegetable 

 character the peculiar premolar teeth would cut off pieces of 

 fruits and other soft parts as suggested by Professor Flower, but 

 that these genera could have been herbivorous in the manner of 

 the existing kangaroos with their full series of molars in both 

 jaws, is clearly inadmissable — E. D. Cope. 



Notes on Eocene Mammalia.— The creodont, Lifodcrtres pene- 

 trans, turns out to be identical with the Deli 

 Dcltadicrium absaroktz must be referred to a new genus with the 

 dental formula I. *; C. |; P-M. J; M. %. The premolars in Del- 

 tatherium are i and in Proviverra |. The fourth superior premo- 

 lar has an internal lobe, and a single trenchant external lobe, and 

 the fourth inferior premolar is different from the first true molar. 

 The genus may be called Didclphodus. 



The Oligotomus osbornianus must be referred to a new genus. 

 If it is not condylarthrous, it must be placed in the Chalicother- 

 iidae, as the most primitive form. The superior true molars have 

 eight cusps, two internal, two intermediate, two principal ex- 

 ternal, and two external rising from the cingulum. The posterior 

 of the latter is opposite the interval between the principal ex- 

 ternal, and if confluent with them would comolete the two ex- 

 ternal V's of the other genera of the family. Inferior molars and 

 last premolar, consisting of two V's. I call it Ectocion. & L> - 



On the Taxeopoda, a New Order of Mammalia.— A further 

 examinationof the carpus of Fkenacodns shows that it is difl< 

 from that of the order Perissodactyla, and agrees wfl 

 the Amblypoda, Proboscidea and Hyracoidea. In the three gro 

 last mentioned, the os magnum supports the lunare,and does 



that of 



