CARBONIFEROUS PLANTS PERU 17 



siders that Calymmotheca Stur represents the fertile forms. 



It is possible, as Kidston remarks (Cat. Pal. Plants, p. 81, 

 1886), that Sphenopteris membranacea Gutbier is only a 

 varietal form of Brongniart's species, which has been iden- 

 tified from a large number of European localities. Brong- 

 niart's type material came from Newcastle, England, Char- 

 leroi, Belgium and Saarbrucken, Germany. 



Potonie considers Sphenopteris royi Lesquereux 8 as a 

 probable North American occurrence of this species, but it 

 is obviously different. Both are characteristic of the Potts- 

 ville formation of the Appalachian coal basin of North Amer- 

 ica and in the uppermost Pottsville they approach very 

 closely to one another and possibly intergrade. 9 



Steinmann's Sphenopteris affinis recorded from Paracas 

 is this species in all probability. S. affinis Lindley & Hutton, 

 which is the same as S. linearis Brongniart, is, except for its 

 Calymmatotheca fructifications, a Diplothmema. It is a char- 

 acteristic type of the Lower Carboniferous of Europe. While 

 this species is variable as to size it appears to me to be dif- 

 ferent from the Paracas material. 



Fuchs called this form Sphenopteris Hartlebenii a Wealden 

 species of Dunkers, since transferred to the genus Ruffordia 

 by Seward. 



Genus EREMOPTERIS Schimper 

 [Traite Pal. Veget., t. i, p. 416, 1869] 



This genus was proposed by Schimper, the type being the 

 Sphenopteris art emisice folia of Sternberg from the English 

 Coal Measures. The question of demarcation between Erem- 

 opteris, Rhacopteris and other genera that might be men- 

 tioned is particularly puzzling and probably insoluble. 



Schimper was also responsible for the name Rhacopteris, 

 the type and only species enumerated by him being based on 



8 Coal Fl., vol. 3, p. 768, pi. 104, figs. 7-10, 1884. 



9 White, D., 20th Ann. Kept. U.S. Geol. Surv., pt. 2, p. 882, 1900. 



