I9I4-] SOUTHEASTERN XORTH AMERICA. 187 



independent family, the Cedrelaceae, has four Wilcox species, Eocene 

 prototypes of existing American species. This genus with 9 or 10 

 species is confined to America in the existing flora and is only known 

 outside this area in two species from the Miocene of Croatia which 

 Unger referred to Cedrela and an undescribed Cedrcla recorded by 

 Ettingshausen from the Ypresian of the south of England. Saporta 

 has, however, recorded six species of Cedretospermum from the San- 

 noisian of southeastern France. The fossil record of these three 

 genera Carapa, Moschoxylon and Cedrela, brief as it is, shows clearly 

 that the Meliacese are not a modern element in the flora of the Amer- 

 ican tropics but one that was already well differentiated in the early 

 Tertiary. 



The remaining fossil references to this family comprise Meliacece- 

 carpum based on capsules from the Aquitanian of Prussia which 

 Menzel their describer compares with those of the genera Dysoxy- 

 lum and Guarea. F. von Miiller has described Rliytidotheca and 

 Ple'wclinus, two supposed meliaceous genera based on fruits, from 

 the Pliocene of Australia. 



The family Humiriaceas is a small one, comprising only three 

 genera and a score of species of shrubs and small trees all of which 

 are confined to the American tropics except a single species found in 

 tropical West Africa, a distribution suggesting a history comparable 

 with that just suggested for Carapa, Moschoxylon and Cedrela. The 

 only known fossil species is one from the Wilcox very close to the 

 existing Vantanea paniculata Urban of northern South America. 



The family Malpighiacese, confined to tropical and subtropical 

 countries, contains about 55 genera and 650 existing species, many of 

 which are scandent, including some of the finest lianas of the tropics 

 with stems 2 dcm. in diameter. Others are shrubs and trees. The 

 leaves are opposite and simple and the fruits drupaceous, capsular, 

 or nutlike, and often winged. The only species that reaches the 

 United States is Byrsonima lucida (Swartz) De Candolle, a small 

 evergreen tree of the Florida keys. 



The family is predominantly American in its distribution, over 

 67 per cent, of both genera and species being confined to the West- 

 ern Hemisphere (37 genera and 440 species). The genera are all 

 local in the sense that none occur in more than one continental area. 



