814 BERRY— TERTIARY FLORAS OE THE [April 21, 



conditions which prevailed along the Miocene coast in this latitude. 

 There is considerable evidence of a scant rainfall, that is to say of 

 less than 30 inches annually but this may well have been merely a 

 coastal condition. Indirectly the lack of land derived sediments in 

 the deposits points to the conclusion that relatively dry conditions 

 extended over wider areas. The mean annual temperature is diffi- 

 cult to determine. Several of the closely allied modern plants such 

 as the existing bald cypress do not extend north of Maryland in the 

 existing flora, while Ficus does not fruit north of Virginia, which 

 also marks the northern limit of Plaiicra. However, the Miocene 

 forms enumerated are all different specifically from the existing 

 members of their respective genera and the conclusion is reached 

 that the Calvert flora would grow under the climatic conditions pre- 

 vailing at the present time between Sandy Hook. X. J., and Cape 

 Henry, Va., and that the mean annual temperature which they indi- 

 cate is between 50° and 55° F. 



Pliocene. 



Pliocene floras have been unknown from Xorth America until 

 last year when deposits of this age with abundant fossil plants were 

 discovered in southern Alabama. The most remarkable form in 

 this flora is the fruit of Tvapa, the water nut, which Raimann in 

 Engler and Prantl segregates from the family Onagraceas to form 

 the family Hydrocaryaceas. In the existing flora this genus has only 

 three species of southern Europe and southeastern Asia but it is 

 well known in the older Tertiary of Xorth America and Europe 

 and in the later fossil floras oi Europe. Another interesting species 

 in this Alabama Pliocene flora is a species of Glyptostrobus, a 

 coniferous genus allied to our bald cypress which is now confined 

 to eastern Asia, but which appears to have been cosmopolitan in 

 Tertiary times. Other elements of this flora are abundant live-oaks 

 ( Qucrcus) ; several species of elm (Ulnms) ; abundant twigs, seeds 

 and cone scales of a species of cypress which is very close to the 

 existing bald cypress ( Taxodium). Additional elements are species 

 of Nyssa, Ilicoria, Plaiicra, Bctula, Dioscorea, Primus, Pinus, etc. 

 This flora is <]uite modern in its facies and is a mixture of swamp 



