SAGENOPTERIS 131 
Type. Detached leaflets of various shapes and sizes. 
Dunker defines his species as follows’ :— 
“‘Cyclopteris fronde . . . . pinnis crassis subpetiolatis, oblique 
cordatis vel cuneato-subrotundis vel ovato-obtusis integris vel sub- 
crenatis, nonnullis apice sinuatis et bilotatis, nervis creberrimis 
flabellatis apicem versus irregulariter dichotomis.” 
The Wealden specimens enable us to give a more complete 
diagnosis of the species. 
Leaf consisting of four leaflets sessile on the apex of the leaf- 
stalk, palmately arranged, variable in shape and dimensions, the 
two upper or terminal leaflets larger than the lower pair, spathu- 
late, obovate or elliptical, margin entire, or with one or two broadly 
rounded lobes. 
Venation reticulate, the meshes elongated in the direction of 
the long axis of the leaf; in some leaflets there is a fairly distinct 
midrib near the point of attachment, but it rapidly dies out 
towards the apex; in some specimens no sign of a midrib. 
Fructification unknown. 
Dunker’s figures? of detached leaflets, if we accept his view 
that they all belong to the same species, sufficiently demonstrate 
the wide limits within which their form and size vary. 
The small specimens figured by Ettingshausen* agree much 
more closely with Aneimidium Klipsteini (Dunk.), and, indeed, he 
includes that species as a synonym of Sagenopteris Mantelli (Dunk.). 
Possibly, as suggested in the above list of synonyms, one of the 
leaflets is that of the present species, but it is by no means certain 
that any of them should be included under the genus Sagenopteris. 
Schenk‘ points out the close connection between Sagenopteris 
Mantelli (Dunk.) and S. rhovfolia, Presl; it seems, indeed, almost 
impossible to draw any distinct line between these two species. 
As a rule the leaflets of the former are smaller and less elliptical 
or elongated than those of the latter, but it is quite conceivable 
that the discovery of more Wealden specimens may compel us 
to recognize more definitely this close agreement between the 
two forms. 
1 Wealdenbildung, p. 10. 
* Loe. cit. pl. ix. fig. 4. 
3 Abh. k.-k. geol. Reichs. vol. i. Abth, iii. No. 2, p. 18. 
4 Paleontographica, vol. xix. p. 223. 
