ORTMANN I TERTIARY INVERTEBRATES. 
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Natica chilo'ensis N. ovoidea. 
Turntella exigua T. ambulacrum. 
Strutliiolaria hatcheri A. amegliinoi (and ornatci). 
Bulla remondi B. patagonica. 
Since these genera belong to the most characteristic forms of these de- 
posits, it is very significant that they are represented by different species, 
and this fact affirms the difference in age of both series indicated by the 
stratigraphical evidence. 
The fact that 4 Navidad species have been discovered in the Magel- 
lanian beds suggests that this latter horizon is also represented within the 
Navidad series. In this respect it is significant that these Navidad species 
have never been found in Patagonia, and it is quite possible that the 
Navidad fauna as described by Philippi contains elements of different age, 
including the Magellanian beds. 
As regards the age of the Magellanian beds we must depend in the first 
line on the stratigraphy, since palaeontology — although suggestive of a 
slightly older age than Patagonian — is altogether insufficent to permit 
any definite opinion. The Magellanian beds are several hundred feet be- 
low the Patagonian, and are separated from them by a coal- deposit ; since 
the Patagonian beds are Lower Miocene, this would bring the Magellanian 
beds into the Oligocene , or perhaps — taking into consideration the changed 
conditions under which the Upper Lignites were deposited — into the 
Upper Eocene. 
It would be very interesting and important to get more material from 
the Magellanian beds. This first indication of this fauna was given by 
Philippi (1887), who described a number of fossils from Punta Arenas 
and Skyring Water. From his list of 16 species (leaving out Turntella 
patagonica , which has been inserted by mistake) the following are repre- 
sented in our collection : 
Haliotis imperforata = Crepidula gregaria. 
Venus chilo'ensis. 
Pa7iopea ibari. 
Pectunculus ibari and niagellanicus (both identical and = Glycimens than). 
Ostrea bourgeoisi and patagonica (both identical and = 0. ingens). 
Ostrea torresi. 
Two of these belong in the Magellanian beds ( Panopea than and Ostrea 
torresi ), while the rest has been found in horizon V, which represents the 
Patagonian beds. 
