88 CLADOPHLEBIS. 
scription agrees with that previously given by himself of the group 
of Jurassic ferns of the type Alethopteris Whitbyensis. Fontaine 
slightly modifies Schimper’s definition, and suggests that with the 
addition of ‘‘midnerve strong at base, and towards the summit 
dissolving into branches,’’ we have a well-defined group of ferns 
‘strongly characteristic of the Jurassic, and which is fully as much 
entitled to be called a genus as is Sphenopteris or Pecopteris.’”! 
In his more recent contributions to the French Jurassic flora, 
Saporta continues to make use of Cladophlebis as a genus, and 
adds that the Carboniferous species originally included by Brong- 
niart in his group Pecopteris Neuropteridis, for which the term 
Cladophlebis was subsequently proposed, have nothing in common 
with the Liassic and Oolitic species of that genus. The Jurassic 
species, he observes, give evidence of common characters which 
point to a well-marked type [ Cladophlebis tenuis (Brong.), C. Whit- 
byensis (Brong.), C. ligata (Phill.), C. Hatburnensis (Lindl.), C. 
lobifolia (Lindl.), and several others, ‘‘se ressemblent entre eux 
et témoignent d’une parenté tenant au moins, a leur physionomie 
commune”’].* Granting the existence of these common characters 
there is still, as Saporta, indeed, recognizes, no evidence from such 
traces of fructification as occur of any true relationship (‘‘con- 
généres’’); indeed, the fructification, so far as it is known at 
all, points to the inclusion of ferns of different families under 
this single generic name. 
We may adopt Schimper’s definition, with certain modifications : 
Fronds pinnately divided, pinne spreading, lobes or pinnules 
attached by the entire base or slightly contracted towards the place 
of attachment, rarely somewhat auriculate, acuminate, or obtuse, 
occasionally dentate, especially at the apex, not rarely subfalcately 
curved upwards, midrib strong at base, and towards the summit 
dissolving into branches, secondary veins given off at a more or 
less acute angle, dichotomous a little above the base, and repeatedly 
dichotomous. 
It should be noted with reference to the present genus that 
Heer‘ has included under Asplenium those Jurassic ferns which 
1 Potomac Flora, p. 67. 
2 Pal. Franc. sér. ii. vol. iv. p. 357. 
3 Trait. pal. vég. vol. iii. p. 513. 
4 Fl. foss. Arct. vol. iv. 1877, p. 38. 
