94 CLADOPHLEBIS. 
between this Potomac species and the English specimens is cer- 
tainly striking; in the former there seems to be no sign of any 
denticulate character in the pinnules; on the whole they ought, 
I think, as Fontaine has decided, to be kept separate. Finally, 
C. inelinata, Font.,’ resembles some portions of C. Albertsiz fronds. 
It should be remembered that the material included in the 
British Museum Collection which I have referred to C. Alberisid, 
under a modified definition, is much more perfect than that at the 
disposal of previous writers; it is not surprising, therefore, that 
some of the species which have been founded on isolated fragments 
are brought into close connection with one another by the exami- 
nation of the fronds of the English specimens. 
It would not be difficult to point to various specimens from 
different parts of the world which can with difficulty be separated 
from the present species; this applies to such forms as are repre- 
sented by Cladophlebis Whitbyensis, Brong., and others. The 
figures given by Oldham and Morris of Pecopteris (Alethopteris) 
Indica, O. and M.,? appear to be very similar indeed to some of our 
specimens of C. Albertsit ; and if such a pinna as the one figured 
in pl. xxvii. fig. 3 were found in European Wealden rocks I 
should have no hesitation in referring it to Dunker’s species. 
Oldham and Morris recognized the great difficulty in attempting 
to separate such forms as Pecopteris Whithyensis, P. dentata, Gopp., 
P. nebbensis, Brong., and several other similar species.* Another 
example of this close resemblance between portions of sterile 
fronds, which come under the provisional designation Cladophlebis, 
is afforded by the fragment figured by Saporta* as C. Réssertz, 
Schenk; this agrees closely with C. Albertsii. Sphenopteris 
flabellifolia, var. erecta, Ten.-Woods, seems to be very like C. 
Albertsii, if not identical. A specimen in the British Museum 
(41417) from the Douglas River Coal-seam in Tasmania is 
probably identical with this Wealden species of Cladophlebis. 
Possibly, as suggested in the synonomy, Asplenium nebbense 
(Brong.), figured by Bartholni from the Jurassic rocks of Born- 
holm, may be regarded as a fragment of Cladophlebis Albertsit. 
The specimens from the English Wealden beds show no traces 
1 Potomac Flora, p. 76, pl. x. figs. 8-4; pl. xx. fig. 7. 
2 Foss. Fl. Gond. vol. i. ser. ii. pt. 1. 1863, p. 47, pl. xxvii. 
3 Ibid. p. 48. 
4 Pal. Frang. vol. i. 1873, pl. xxxi. fig. 4. 
