J. B. Hatcher — Geology of Southern Patagonia. 331 



isted with the Dinosaurs of that period. From a study of the 

 figures and descriptions published by Dr. Ameghino of the 

 fossils found in the Pyrotherium beds, one is even led to 

 believe that they may belong to a period more recent than that 

 of the Santa Cruz beds. I present here in fig. 2, taken from 

 one of Ameghino's latest publications, the superior dentition of 

 Morphippus imbricatus, one of the smaller ungulates described 

 by him as coming from the Cretaceous of Patagonia. 



Fig. 2. Sup. dentition of Morphippus imbricatus Amegb., after Ameghino. 

 One-half nat. size. 



The entirely molariform condition of the premolars and the 

 cupped incisors are especially noteworthy. In his " JSTotes on 

 the Geology and Paleontology of Argentina " previously 

 referred to, he says on page 8, in speaking of the Pyrotherinm 

 fauna, " The unarmored edentates are also numerous and of 

 types resembling those of the Santa Cruz formation, but 

 generally of much more considerable size. Nevertheless some 

 forms show very primitive characters, having the molars pro- 

 vided with a well developed layer of enamel. 



" With these edentates there are Carnivorous animals of a 

 size approximating to that of the largest bears of the present 

 day, but similar to those of the Santa Cruz formation." This 

 is certainly a greater size than that attained by any of the Car- 

 nivorous animals of the Santa Cruz beds. Moreover many of 



