PLIOCENE PISLLYPAMPA BOLIVIA 161 



are, in my judgment, of generic rank, and the present fossil 

 species appears to be referable to the ninth of Christensen's 

 groups the genus Goniopteris of Presl. 



The genus Goniopteris comprises about 60 existing species, 

 largely confined to the American tropics, but said to be spar- 

 ingly represented in Africa, Asia and Australia. Among 

 previously described fossil forms the present species appears 

 to be most similar to Goniopteris claiborniana Berry 10 from 

 the late middle Eocene of Mississippi and Louisiana (Yegua 

 formation), differing in the degree of incision of the margin 

 and in the less complex venation, but identical in general 

 form, habit, winged rachis, etc. The Bolivian species is, 

 however, thicker textured. Entirely too little is known of 

 the ferns of the eastern Bolivian lowlands or of the upper 

 Amazon basin to enable me to make proper comparisons with 

 the existing species in those regions, but I have not the 

 slightest doubt that species, closely similar to the fossil, are 

 present in the well watered and lower montana country east 

 of the present Andes, as I know that they are present in 

 that general region. 



The following are some of the existing species that are 

 very similar to the fossil : the common Dryopteris patens 

 (Desv.), widespread in the American tropics; Dryopteris 

 riparium (Mor.), Dryopteris gonylodes (Schk.), Dryopter- 

 is monostichum (Kunze), Phegopteris brachyodes Mett., and 

 Phegoptcris tetragona Mett., all forms of the South Ameri- 

 can equatorial region. Other existing species in that region 

 are probably closely related, since I have made no extended 

 search in herbaria, nor have I sought to correct the obsolete 

 nomenclature in the case of the forms cited. The fossil also 

 resembles somewhat Hemitelia grandi folia Sprengel of the 

 Antilles, northern Andes and northern Brazil in the form of 

 the pinnae and position of the sori, differing in venation in 

 not having anastomosis confined to the extreme base of the 



10 Berry, E. W., Bull o Torr. hot. Club, vol. 44, pp. 331-335, pi- 22, 

 1917. 



