32 8 THROUGH THE HEART OF PATAGONIA 



Large Extinct Rodent. 



The proximal end of the femur of a large rodent has already been 

 recognised by Roth, and compared with the extinct Megamys. It cannot 

 be more exactly determined. 



Existing Species. 



One imperfect fragment of pelvis and sacrum seems to belong to 

 a puma {Felis concolor) of rather large size ; but it is not sufficient for 

 precise determination. 



The small mandibular ramus of a musteline referred by Dr. Roth 

 to Mephitis suffocans, does not pertain to this genus and species. 

 Mr. Oldfield Thomas determines it to belong to the rare Lyncodon 

 patagonicus, which still lives in Patagonia and has not hitherto been found 

 fossil. A slightly larger extinct species of the same genus has been 

 described by Ameghino on the evidence of a skull from the Pampean 

 formation near Lujan, in the Province of Buenos Aires.* 



A cranium, some vertebrse, and a tibia and fibula appear to represent 

 the existing Ctenomys magellanicus, as noted by Roth. 



The remains of the Guanaco {Lama huanacos) do not present any 

 features worthy of special remark. 



Man is represented by a diseased scapula and by two bone awls, which 

 are clearly made from the tibia of a species of Canis intermediate in 

 size between C. jubatus and C. magellanicus. 



3. Relative Age or the Remains. 



As the result of Dr. Roth's researches, supplemented by the additional 

 observations now recorded, it is evident that the majority of the mam- 

 malian remains from the cavern near Last Hope Inlet belong to the 

 extinct fauna which occurs in the Pampean formation of more northern 

 regions. To this category are referable the genera Grypotherium, Onohip- 

 pidium, Megamys, and Arctotherium ; also Macrauchenia, which is said to 

 have been discovered in the same deposit on the floor of the cave by 

 Dr. E. Nordenskjold. The large Felis likewise probably belongs to the 

 same series. Remains of mammals of the existing fauna, on the other 

 hand, are comparatively few and insignificant, referable to the genera 

 Ctenomys, Cervus, Lama, Lyncodon, and Felis. 



"* F. Ameghino, op. cit. (1889), p. 324. 



