MESOZOIC PLANTS PERU 47 



Undoubtedly there is a splendid flora hidden in the Meso- 

 zoic rocks of Peru which would repay the work of experi- 

 enced collectors, but the localities are so remote and diffi- 

 cult of access that it will doubtless be many years before 

 we can hope to know much about it. My own collections 

 are limited to a small amount of material from Pifionate 

 near Lima, a large collection from Caleta de Paraiso on San 

 Lorenzo Island and three specimens from Jatunhuasi, De- 

 partment Junin obtained from Senor Bravo. 



An attempt is made in the following pages to sum up our 

 present knowledge of the Peruvian Mesozoic flora. With 

 the exception of Sal f eld previous contributors have accepted 

 without question the Wealden or Neocomian age of these 

 various plant-bearing outcrops. According to the deter- 

 minations of Lisson the plant beds at Pifionate and Paraiso 

 lie between marine Portlandian and marine Valanginian. It 

 may be again emphasized that the term Wealden is not a 

 satisfactory chronologic term since the name, even in Europe, 

 connotes a type of deposition of no exact time value and its 

 application in various other parts of the world is most un- 

 fortunate. Certainly the flora from Peru contains nothing 

 that conclusively proves its Neocomian age. Most of the 

 discovered forms are distinctly Jurassic types which brings 

 up the old question of the lack of a decisive paleobotanical 

 boundary between the Jurassic and Lower Cretaceous that 

 has been raised in so many other regions. My own con- 

 clusion is that it would be nearer the true facts to refer these 

 Peruvian plant-bearing beds to the Portlandian stage rather 

 than perpetuate the indefinite term Wealden. 



The lithology of the plant-bearing beds on San Lorenzo 

 Island is especially interesting and I append the following 

 notes on the lithology kindly furnished by Dr. M. I. Gold- 

 man, the well-known authority on the study of sediments. 



"In the hand specimen a light colored, pearl-gray shale, 

 hard, with a rather soapy feel, probably due to the film of 



