DICTYOPHYLLUM 141 
acutilobum,! Schenk, in its venation and the arrangement of the 
sori, A similar regular disposition of sporangia is shown in Heer’s 
Lower Cretaceous species from Greenland, D, Dicksoni,? Hr. 
Fie. 16 (V. 21774). Dictyophyllum Roemeri. Twice natural size. 
V. 21775. Fig. 16. 
A small piece of a frond showing portions of three chief veins 
and, between them, a reticulum of smaller veins. In the meshes 
of the finer veins there occur small depressions which probably 
represent sporangia; here and there these appear to have a fairly 
regular arrangement. Cf. Dietyophyllum Dicksoni, Heer, F1. foss. 
Arct. vol. i. pl. iii. figs. 9 and 94, 9¢ and 9d. 
In this specimen the finer reticulation is not nearly so apparent 
as in Schenk’s figure, but, in the absence of more satisfactory 
evidence, I prefer to adopt his specific name, although possibly 
more perfect material may show that the English specimens belong 
to a separate species. Cf. also some of the figures of Hausmannia 
Forchhammert, Barth., e.g. pl. xi. figs. 4 and 4a. Ecclesbourne. 
Rufford Coll. 
V. 2177. A similar fragment to V. 21775. Traces of sporangial 
depressions in some of the meshes. 
Ey 
Fic. 17 (V. 2177a). Dietyophyllum Roemeri. Twice natural size. 
Ve 21 Wia) Bis. 17. 
Small piece of leaf showing the venation very clearly, as a 
carbonaceous reticulum. Ecclesbourne. Rufford Coll, 
1 Fl. foss. Grenz. Keup. Lias, pl. xx. 
? Flor. foss. Arct. vol. ili. pl. iii. fig. 9. 
3 Bartholni, Joe. cit. 
