180 General Notes. [ February, 
of hook towards the east formed by Tierra.del Fuego and Staten 
island, indicates the direction of the crest of this submerged con- 
tinent. This subsidence of Patagonia, following an elevation 
which has left salt lakes with still-living marine species 200 feet 
above the sea, is balanced by an elevation to the north of the Rio 
de la Plata. There the same upward movement of submarine 
formations which has caused the canal to the east of the Patago- 
nian Andes to be abandoned by the sea, while that to the west 
parts off a chain of multitudinous islands, is now in operation 
farther north. Modern alluvium, formed by great lakes fed by 
the melting glaciers, have filled up the old sea-canal to the east 
of the Patagonian Andes. An alternation of partial subsidences 
and elevations, such as are now acting, allowed the fauna to per 
sist, and caused that alternation of marine and terrestrial beds 
which is observable. a 
Towards the middle of the Tertiary period, the two Americas 
were as yet disunited, Southern Brazil was a great island, the By 
filling the basins of the Amazons and the La Plata ; the mass ° 
the Columbian mountains stretched to the north, while Bolivia and 
Patagonia, now separated from the southern continent, form reel | 
vast peninsula. The numerous groups of islands dotted over’ ch | 
Pacific seem to be the remains of the submerged continent which 
united Australia to South America, According to Hooker” 
less than seventy-seven species of plants are common to A | 
Zealand, Tasmania and South America, whilst very few psat | 
politan genera are common to these regions. The presence | 
marsupials is another link between Australia and South a ; 
Probably Australia was parted off at the end of the oa gh | 
period, while South America was still a portion of the ses 
continent. The marsupials were thus divided and evolved ap 
rately in their two seats, while in the Miocene the edentates “£ 
the remains of Mesotherium, is probably the old 
known in Patagonia, and extends over a large area tO. ~ 
and south-west. An ancient shore near Lake Argentine Py 
the subsidence of Patagonia toward the end of then 
period. nai 
Sr. Moreno believes that the present relief of Patagonia Te 
result of volcanic eruptions which, towards the end of ver : 
tiary, were repeated from Tierra del Fuego to Brazil. + “ce gb 
influence of these Patagonia rose again, but the antarctle "espis 
advanced and the land was glaciated. The pampean !9. fore 
the result of the far-spreading glaciation produced, 19 or a init : 
no s opinion, by astronomical causes, and the remains ae ; 
Were carried by the ice from more southern parts—"" mp 
complete skeleton is found in the true silt of the lower t " 
~ 
