92 STUDIES IN GEOLOGY, No. 4 



of !Piper, often given generic rank. The material on which 

 the fossil record was based is scanty and does not merit the 

 attempt to identify it, much less to definitely assign it to 

 Artanthe, although one would expect the Piperacese to be 

 represented in this fossil flora. The present record does not, 

 however, satisfy this expectation. 



The Urticales, the first order of Dicotyledonae to be con- 

 sidered, is represented by a single, somewhat doubtfully 

 determined species which Engelhardt refers to Coussapoa 

 and compares with the existing Coussapoa asperifolia Tre- 

 cul of the Guayana region. The genus Coussapoa comprises 

 about 15 existing species of Central and northern South 

 America which have very characteristic leaves both as re- 

 gards form and venation. The Chilean record is extremely 

 inconclusive. Three fossil species rest upon more satis- 

 factory evidence. These occur in the Miocene of the foot- 

 hills of the Sierra de Merida in Venezuela, in the Miocene 

 of southern Mexico, and in the Pliocene of the Sierra de 

 Cochabamba in Bolivia. 



Strangely enough, the genus Ficus, so abundantly repre- 

 sented in the existing flora of tropical Soujh America, and 

 present in most Tertiary floras, is apparently absent from 

 the Chilean Miocene. I can scarcely account for this except 

 by falling back on the imperfection of the geologic record 

 and assuming that Ficus will eventually be discovered in this 

 flora as a result of future exploration. 



Other families which are absent and which one would 

 expect to find represented are the Musaceae, Sapotacese, Me- 

 lastomatacese, Malpighiaceae, Trigoniacese and Anacardiaceae, 

 all of which are prominent at the present time in the South 

 American tropics and many of which are already known in 

 the few South American Tertiary floras that have been 

 described. 



The order Santalales is represented by the family Loran- 

 thaceae with two species in the genera Psittacanthus and 

 Antidaphne. The former which is similar to the existing 



