4 PROCEEDINGS OF THE NATIONAL MUSEUM vol. to 



and consequently a vegetation normal to the latitude, and not such 

 as has existed since the Andes were elevated. This Oligocene flora 

 has not yet been described in print because of the great difficulty in 

 making precise identifications of some of its members. 



It seems scarcely possible that there should have been high moun- 

 tains and a desert in their rain shadow during the middle Eocene 

 when the border lands of Colombia, Ecuador, and Panama were 

 submerged by the first transgression of the Tertiary sea, at a time 

 when seaways were formed between the two oceans, and the sedi- 

 ments of which contain a common fauna. This is especially diffi- 

 cult to envisage because in the continuous series of deposits in north- 

 western Peru we find the Eocene passing into the Oligocene without 

 any apparent structural break or faunal hiatus, and the indicated 

 climate of the latter is moist and precludes high mountains, 



I am indebted to O. F. Cook, our well known authority on living 

 palms, for having examined these fossil fruits, and he is inclined to 

 think that both the genera Attalea and Astrocaryum are represented. 

 This may well be the case, but I can not see any generic differences 

 among the 12 specimens which I have studied, and which I have 

 accordingly referred to the second of these genera, to which the re- 

 lationship seems the more conclusive. 



Both genera include stemless to tall feather palms, with numerous 

 species confined to America. Astrocaryum Meyer has about 30 ex- 

 isting species, ranging from southern Mexico to eastern Peru, and 

 reaching their maximum in the rain forests of the Amazon basin, 

 but also found in the Brazilian Campos. Although not a coastal 

 type, rivers contribute its fruits to ocean currents and its empty 

 fruits are recorded in the beach drift of both coasts of tropical 

 America and the Azores by Guppy. The genus Attalea Hmnboldt, 

 Bonpland, and Kunth contains about 25 existing species, ranging 

 from Honduras to Colombia and southern Brazil, and along the 

 eastern Andes to the Yungas of Boliva. Its fruits have not been 

 recorded in the beacli drift so far as I have been able to ascertain, 



EXPLANATION OF PLATE 



Figs. 1-4. — Astrocariium olssoni Berry- From Eocene of Negritos, Peru. 



1, 2. Side view of a large and small nut, figure 2 shows the outer longitu- 

 dinal fibers in the middle region. 



3. Side view of a more spherical nut showing the inner, transversely 



rugose surface. 



4. Proximal view of a nut showing perforation. 



o 



