40 THE FLORA OF THE AMBOY CLAYS. 
published, and it will be seen that the closest correspondence exists in all 
particulars between the Greenland and New Jersey specimens. The 
geological importance of this identification is apparent, and is quite inde- 
pendent of the yet undecided question of the botanical relations of this 
plant. Professor Schimper (Paléontologie Véeétale, Tome I, p. 660) refers 
this fern to Asplenium, like all those with which it is associated geolog- 
icaliy and botanically, viz, Asplenium Brongniarti Deb. & Ett., A. Foersteri 
Deb. & Ett., A. cwnopteroides Deb. & Ett., and A. subcretaceum Sap. Professor 
Heer adopts this view, and in his Flora Arctica, Vol. III, he changes the 
name of the fern under consideration from Sphenopteris to Asplenium. 
This harmony of opinion among the distinguished botanists whose names 
have been mentioned must carry with it great weight, but it is necessary 
to say that it is based on the general similarity of form and nervation, and 
that, the fructification of none of these ferns having been yet found, the 
question of their generic relationship can not be said to be decided. From 
the absence of fruit in all these plants, which he takes as evidence that the 
fertile and sterile fronds were borne on distinct stipes, as well as from 
the resemblance of the vegetative organs, Mr. J. Starkie Gardner, in his 
Monograph of the British Eocene Flora, decides to refer Asplenium subcre- 
taceum Saporta to Anemia. This question is discussed at some length in 
my notes on the allied and associated species, Asplenium Foersteri, and it 
need not be further pursued here. 
As in A. Foersteri, the fronds of this fern were evidently somewhat 
thick and coriaceous; the surface is polished, and the nervation is generally 
obscure; the stipes are fluted, a central ridge being bordered by a more or 
less distinct furrow on either side. From this ridge a nerve passes through 
the center of each pinna, and this midrib gives rise to a slender nerve fiber 
which traverses each pinnule to the apex. In a few specimens it may 
also be seen that delicate side nerves are given off by the midrib of each 
pinnule. 
Locality: Woodbridge. 
