636 White — New Fossil Plant from Bahia, Brazil. 



once apparent from an inspection of the figures. Mention 

 may in particular be made of Alethopteris aqailina, and some 

 of the narrowest-pinnuled portions of the pinnae of Alethopteris 

 granclini. The nearest resemblance of the specimens in hand 

 is, however, with the latest Paleozoic representatives of the 

 genus, such, for example, as Alethopteris Virginiana F. & I. 

 C. W.,* from theDunkard formation in southwestern Pennsyl- 

 vania and northern West Virginia. The later species of the 

 genus are specially characterized by the more open and less 

 decurrent pinnules and midribs, the generally thick texture of 

 the lamina, and the close, very open, and often simple nerva- 

 tion. 



The species described above presents a strong superficial re- 

 semblance to fronds from the Raniganj coal field (Permian V) of 

 India, described by O. Feistmantel as Alethopteris phegopter- 

 oides. Our plant differs, however, from the specimen so beauti- 

 fully illustrated in Part II, vol. Ill of the Memoirs of the Geo- 

 ical Survey of India (p. 81, pi. xvin-a, fig. 1) by the less 

 crowded and more tapering pinnules and the more open nerves. 

 The nervation of the Indian specimen is simple. 



Regarding the age of the beds from which the fragments here 

 described were obtained, we have no other evidence than that 

 presented by the fossils themselves. Beds of Cretaceous age 

 are known in the general region, but the frond fragments sub- 

 mitted by Doctor Branner come from a formation and series of 

 unknown age. If the fragments are correctly, as I believe, 

 referred to Alethopteris, the plant beds may be assumed to be 

 Paleozoic and very likely Upper Coal Measures or Permian in 

 age. The evidence for any age is very scant : but so far as 

 it goes it appears to point toward the Carboniferous period. 

 Pending the collection of additional material showing not only 

 the true character of the nervation of Alethopteris Branneri, 

 but also bringing to light other types, the question of the age 

 of the plant bed should be treated with extreme caution, for 

 although fronds of an Alethopteroid aspect are very rare in the 

 Mesozoic, but few forms even resembling the plant in hand 

 having hitherto been described, f it should not be forgotten that 

 similar types may, nevertheless, have been present in South 

 America, and that fronds presenting a superficial similarity to 

 Alethopteris are present among living species of Pteris, 

 Mertensia, Aspidium, and other genera. 



*Second Geol. Surv. Pa., Eept. of Progress PP, p. 88, pis. xxxii and xxxiii. 



f The fragments described are slightly suggestive of that figured by Nathorst 

 as Pecopteris Angelini from the Rhetic of Scania, (K. Svensk. Vetensk. 

 Akad., Handl., vol. xvi. No. 7, 1878, p. 12, pi. I, f. 7.) 



