-< 1893.] Fossil Mammalia of Southern Patagonia. 449 
lations of volcanic detritus. The Pehuelche is of fluviatile 
origin. Is it necessary to repeat for the hundredth time, that 
there is not the least vestige of glacial action in the Pampean 
formation ? 
It is impossible to name single fossil species from the Pam- 
pean formation which is characteristic of a colder climate 
than now prevails in the same country. On the contrary, not 
only does the mammalian fauna indicate a warmer climate 
` than at present, but the fresh water conchological fauna also 
furnishes similar evidence. The many fossil plants of the 
` Pampean formation are the same that are seen to-day in the 
province of Buenos-Ayres, or in the northern part of the 
Argentine Republic—not a single form belonging to a cold cli- 
mate. I am almost certain that an examination of the marine 
_ shells of the same formation would lead to the same result. I 
am about to make a collection of them to send to M. von 
Jhering, whom I will request to study them from this point of 
view. 
