DESCKIPTION OF SPECIES— GUPDLIFEll^. 147 



uncertainty is evident from Unger's synonymy, and is still more forcibly 

 suggested by the fact that no species oi' Fagus has leaves with doubly den- 

 tate borders. This is a question, however, which has to be decided by 

 European authors. 



Habitat. — Elko, Nevada (Prof. E. D. Cope). The two specimens from 

 Golden described under this specific name in Annual Report, 1872, p. ^78, 

 are mere fragments, too imperfect for satisfactory determination. The same 

 remark is applicable to the single leaf referred to Fagus Deucalmiis, Ung., from 

 Evanston specimens, in Annual Report, 1871. p. 292. 



aUERCUS, Linn. 



The distribution of the Oaks at the present time affords some interesting 

 data, which may be considered with reference to what is known of the devel- 

 opment of the genus in the geological times. 



Of the two hundred and eighty species described in the Prodromus, the 

 North American continent has for its share one hundred and twenty-one, 

 thirty of which belong to the United States, including New Mexico, and 

 eighty-five to Mexico, most of them, at least ; for a few species descend far- 

 ther south to Costa Rica, even to New Granada, one of these being found in 

 the mountains near Bogota, 5° north of the equator. Of the twenty-five 

 species which are credited to Europe, nine are Mediterranean, passing to 

 North Africa and to Western Asia. None but these Mediterranean species 

 have been found upon the continent of Africa. From Asia, one hundred and 

 twenty species are described, a large number from the southern peninsula 

 and from the depending islands, Java and Sumatra; even a few from the 

 Philippines and Celebes Islands. In that continent, the genus extends its 

 representatives to 5° south of the equator. Japan is credited with nineteen 

 species. From this we see that the Oaks belong to the northern hemisphere 

 nearly exclusively, as very few species pass below the equator in Asia, and 

 as South America, Australia, and Africa (except those of the southern shores 

 of the Mediterranean) have none. This fact is worth remarking, as the range 

 of habitat of the Oaks is as variable as the characters of their leaves; and 

 therefore they should have, more than any other genera, by their facility of 

 adaptation to every kind of climatic circumstance, a world-wide, or at least 

 a more general, distribution. Considering the species of the eastern slope of 

 tlie United States, Gray's Statistics of the Flora gives to Quercus palustris a 



