388 C. SKOTTSBERG 



o{ Xo/Ziofcii^iis. A^e proposed b\' HKkRV (jJ4) Lowest Miocene or Upper Oligocene, 

 then \-oun<^er than the Ma^allancs flora. 



r/if Mdi^iil/cvns fiord. — DusKX [yQ) distin^uislied two plant-bearing horizons, 

 an upper Ayaucafia horizon and a lower Xothofagus horizon. Of the remaining 

 dicots'lons genera none were identified with living ones; DUSEX preferred to call 

 them liscalliuiiipJirUiDii. I lydnvioeiphylliDu etc. There is no obviously tropical 

 eletnent, it is a temperate flora. DlSKX regarded the two horizons as distinctly 

 different in age, dating the upper to Lower ^Miocene, the lower to, perhaps, 

 Oligocene. Hkrrv. who doubted the correctness of this distinction, regarded them 

 as older than the Concepcion-Arauco flora, which seems improbable. 



riie Snuioin- flora. — To judge from DusKX's description (cVo) the tropical 

 element is not conspicuous, whereas the actual South Chilean forest flora is well 

 represented: Araucaria (nearly related to A. araiicaua), Drimys, Xotfiofagus., 

 L'aldcluria, lAUirelia, I.oDiatia, all supposed to be of Antarctic parentage; lean 

 see little reason for I^KKR\'s assertion that the Seymour flora contains "a large 

 element of subtropical or warm temperate types like those found to-day in south- 

 ern Hrazil" together with "another large element of forms suggestive of the 

 existing temperate flora of Southern Chile and Patagonia"; the former was sub- 

 tropical and coastal, the latter temj^erate and montane, washed down, DuSEN 

 thought, from the mountains and embedded together with the leaves of the low- 

 land trees. The age was estimated to be Upper Eocene. Florin's discovery of a 

 species of Aonopyle [I^liyllites sj)., DlSEx) is of particular interest [338]. 



We have seen that Berry considered the Xotfiofagus beds to be older than 

 the Arauco-Pichileufu deposits. y\ll the local fossil floras of Patagonia are, he 

 says [333], older than the marine Patagonian transgression and undoubtedly pre- 

 Miocene. P'rexcueli,! distinguished three epochs: (a) Late Cretaceous to early 

 lv)cene, with a tropical flora, known from the Chali'a beds; (b) an intermediate 

 period with subtropical and temperate types [Xotfiofagus) mixed; to this he would, 

 1 suppose, refer the Seymour flora; (c) the youngest epoch, Miocene-Pliocene, 

 evident!)' extending into Pleistocene: a temperate flora, now ranging along both 

 sides of the southern Andes and characterized by the dominance of A^otfiofagus 

 and ot a number of conifers. The more or less corresponding development of 

 the Andes was according to I5ERRV (2S): (i) I'^ocene-early Miocene: low relief, 

 no high continuous mountains, followed by (2) a period of great uplift; (3) late 

 Miocene to early Pliocene: mature erosion, low relief; (4) late Pliocene to Pleis- 

 tocene: extensive uplift, beginning of the formation of the Chilean and Peruvian 

 deeps, where earlier there was land; (5) submergence of the coastal plain. Finally, 

 but not mentioned by HlRRV, the series of glacial and interglacial periods, a 

 most important factor of disturbance. 



'I his is tlie background against which we have to discuss the history of the 

 Juan I'ernandez flora. 



