192 Berry — Engelhardtia from the American Eocene. 



in the relatively short time, geologically speaking, which has 

 elapsed since the close of the Cretaceous. 



The principle has frequently been enunciated that when 

 closely related forms are found in the existing flora of the 

 world, restricted in range and isolated from their nearest 

 relatives, or when the existing genera are monotypic, it is quite 

 safe to predict an interesting and extended geological history. 

 Engelhardtia proves to be another illustration of this princi- 

 ple, for its peculiar three-winged fruits have been known in the 

 fossil state for almost a century. They were long unrecog- 

 nized, however, and the earlier students who described them 

 compared them with the somewhat similar winged fruits of the 

 genus Carpinus (Betulacese). With the botanical exploration 

 of distant lands in the early part of the 19th century, specimens 

 of Engelhardtia began to be represented in the larger European 

 herbaria, and Baron Ettingshausen,* that most sagacious of 

 paleobotanists, as long ago as 1851 pointed out that certain 

 supposed species of Carpinus were really fruits of Engelhard- 

 tia. He returned to the subject in 1858f without, however, 

 actually changing the names of any of the supposed species of 

 Carpinus nor does he seem to have been aware of the existence 

 of a living species of Engelhardtia in Central America. 



Since Ettingshausen's announcement a dozen or more fossil 

 species have been described. The oldest known occurs in the 

 upper Eocene or lower Oligocene (Ligurien) of France and the 

 species become increasingly abundant throughout southern 

 Europe especially toward the close of the Oligocene and the 

 dawn of the Miocene, Saporta stating that the slabs from the 

 leaf-beds at Armissan in southeastern France are thickly strewn 

 with their peculiar fruits. Fossil forms continue in Europe 

 throughout the Miocene and Pliocene and specimens of late 

 Miocene or early Pliocene age are recorded from Spain, France, 

 Italy, Croatia and Hungary. 



The accompanying sketch map of the world (fig. 1) shows 

 the existing distribution of Engelhardtia and Oreomunnea some- 

 what generalized and exaggerated in order to be seen on so 

 small a scale map. The Tertiary occurrences of Engelhardtia 

 are indicated by stars, a single star covering all of the records 

 in a single area, as for example, southeastern France, from 

 which one Ligurien, three Tongrien, five Aquitanien and one 

 Pontien occurrences have been recorded. No fossil American 

 species have been previously known with any degree of cer- 

 tainty. Lesquereux^: in 1883 recorded Engelhardtia oxyptera 



* Ettingshausen, Die Tert. Fl. von Wien, Abhandl. k.k. geol. Reichsan- 

 stalt. Wien, xi (3), p. 2, 1851. 



f Ettingsha/usen, Beiter. z. Kennt. f oss. Fl. von Sotzka, Sitzungsb. k. Akad. 

 Wiss. Wien, xxviii, 1858, p. 12, pi. iv, fig. 4 ; pi. v, figs. 1-3. 



t Lesquereux, Cret. and Tert. Fl., U. S. Geol. Surv. Terr., vol. viii, p. 192, 

 1883. 



