XXVIl] APHLEBIA 525 



those already referred to as conforming to Neuropteridium, and 

 it is difficult to recognise any reason for the creation of a new 

 generic name. 



We cannot hope to arrive at any satisfactory decision in 

 regard to the precise affinity between Neuropteridium validum 

 and species referred to Gardiopteris and other genera so long as 

 portions of sterile fronds are the only tests at our disposal. It 

 is difficult to determine whether a specimen consisting of an 

 axis bearing pinnules represents a large pinna of a bipinnate 

 frond or if it is a complete pinnate leaf. There is, however, 

 no adequate reason for supposing that the presumably 

 pinnate fronds from the Gondwana Land rocks are generically 

 distinct from the Lower Carboniferous European species 

 Gardiopteris frondosa. Granting the probability that both 

 genera are Pteridosperms and closely allied to one another, the 

 two generic names may be retained on the ground of long usage 

 and in default of satisfactory evidence confirmatory of generic 

 identity. Gardiopteris would thus stand for a type of frond 

 characteristic of the Lower Carboniferous strata of Europe, 

 while Neuropteridium is retained for the Southern species 

 N. validum, and for others from the Trias of the Vosges. 



Aphlebia. 



This name was proposed by PresP for large leaf-like 

 impressions having a pinnate or pinnatifid form and characterised 

 by a confused irregular type of venation, or by a fine superficial 

 striation or wrinkling which simulates veins. Gutbier had 

 previously described similar fossils as Fucoides, and other 

 authors have described Aphlebiae as species of Rhacophyllum, 

 Schizopteris, and other general The term Aphlebia is retained, 

 not as denoting a distinct genus but (i) as a descriptive name 

 for detached leafy structures similar to those figured by Presl, 

 which are now recognised as laminar appendages of the petioles 

 of ferns or fern-like fronds, and (ii) as an epithet for highly 

 modified pinnules which frequently occur at the base of the 



1 Presl, in Sternberg (38) A. 



2 For synonymy, see Zeiller (88) A. p. 301. 



