DICTYOPHYLLUM 141 



acutilolum* Schenk, in its venation and the arrangement of the 

 son. A similar regular disposition of sporangia is shown in Ileer's 

 Lower Cretaceous species from Greenland, D. Dicksoni* Hr. 



FIG. 16 (V. 21775). 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. Dictyophyllum Dicksoni, Heer, Fl. foss. 

 Arct. vol. iii. pi. iii. figs. 9 and 95, 9c 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 Hammannia 

 Forchhammeri, Earth., e.g. pi. xi. figs. 4 and 4#. 3 Ecclesbourne. 



Ru/ord Coll. 



V. 2177. A similar fragment to V. 21775. Traces of sporangial 

 depressions in some of the meshes. 



FIG. 17 (V. 2177). Dictyophyllum Roemeri. Twice natural size. 



V. 21770. Fig. 17. 



Small piece of leaf showing the venation very clearly, as a 

 carbonaceous reticulum. Ecclesbourne. Eufford Coll. 



1 Fl. foss. Grenz. Keup. Lias, pi. xx. 



2 Flor. foss. Arct. vol. iii. pi. iii. fig. 9. 



3 Bartholni, loc. cit. 



