490 



THE AMERICAN NATURALIST [Vol. XL 



The next period, the OHgocene, shows a considerable broaden- 

 ing out in their development and distribution. From the vindo- 

 bonensis type we get, by a series of slight gradations, Comptonia 

 oeningensis, and by ecjually sliglit steps this type gives rise to that 

 most beautiful species, f 'oui pfon ia larhiiala with its large leaves 

 and serrated lobes. This form i> sTroiinly sugu-ested in the leaves 

 of the modern species. The small-leaved types of schranhii and 

 diforme continue through this period, and near them we have the 

 large and handsome form, Compionia drijdiidroidvs, so like the 

 modern leaf, besides two or three other s])ecies of more doubtful 

 value — in all twelve species. 



It is in the next period, however, the Miocene, that the genus 

 reaches its acme of development. Numerous leaf remains, often 

 beautifully preserved, are present at nearly every locality where 

 plant beds of this age have been opened, from (ireece and Bohemia 

 to France and the Bahic. We find a continuation and further 

 development of all of the OHgocene types, the small schrankii with 

 both rounded and acute lobes, the somewhat larger and rather 



ncnsi.s, and the related large-leaved laritiiata and dri/androidrs, 

 besides numerous other forms, including the gigantic (jrandijolia. 



find lariuiafa o-ettinu' ov(M- into Asia Minor from southeastern 

 KurojH'. Ka^t.'n, A.ia ufapani furiiishr^ two o. i sprci,-. which 



