At Bahia Blanca, in latitude 39 degrees south, the most abundant shells were three species of Oliva (one of large size), one or two Volutas, and a Terebra.

Now these are amongst the best characterised tropical forms.

It is doubtful whether even one small species of Oliva exists on the southern shores of Europe, and there are no species of the two other genera.

If a geologist were to find in latitude 39 degrees on the coast of Portugal a bed containing numerous shells belonging to three species of Oliva, to a Voluta, and Terebra, he would probably assert that the climate at the period of their existence must have been tropical; but, judging from South America, such an inference might be erroneous.
The equable, humid, and windy climate of Tierra del Fuego extends, with only a small increase of heat, for many degrees along the west coast of the continent.

The forests for 600 miles northward of Cape Horn, have a very similar aspect.