434 Dr. 8topes — Cretaceous Plant from Nigeria. 



carbonaceous, and characteristically regular meshwork (see Figs. 1-3, 

 PI. XXXIII). In the majority of cases the mesh is isodiametric, and 

 about 2 mm. across, but toward the edge or base of the specimens the 

 mesh narrows and becomes reduced in size, as is shown in the Text- 

 figure, p. 435, and Fig. 3, PI. XXXIII. In a few cases the whole 

 of the mesh is finer. 



The first point to determine is whether this open mesh represents 

 a normally perforate leaf or macerated portions which retain only 

 the skeletal framework. The former interpretation would seem 

 reasonable were there not a few cases in which a blackened, coaly 

 film lies over part of the area and suggests that it was the surface 

 tissue of a non-perforate leaf lamina. In living reeds a somewhat 

 similar phenomenon can be observed on a smaller scale ; the leaf-base 

 in Typha partially decays, displaying a regularly perforated skeleton 

 beneath the smooth lamina, and I feel little doubt that the fossils 

 represent old leaf-bases of somewhat similar plants. 



Turning now to described species of fossils with which to compare 

 the new Nigerian plant, one finds a number of records of Arundo, 

 Typha, Phragmites, etc., from the Tertiary of many countries. None 

 of these specimens, however, are identical with our fossil, the forms 

 generally being laminse which only show fine striations formed by 

 the longitudinally running veins and their regular transverse 

 connexions. The same may be said of the forms described by Heer, 

 linger, Saporta, and others from the Cretaceous, as will be seen in 

 the various original figures, references to which are given in detail in 

 my Cretaceous Catalogue ' under the generic names. Among the 

 illustrations of comparable forms which I have been able to discover 

 fig. 2a, pi. xviii, of Lud wig's- paper on the Tertiary species 

 Phragmites Oe^iingensis, Al. Braun, bears considerable resemblance 

 to a fragment of our fossil; but this figure is an enlargement of the 

 detail of the leaf; the normal leaf of P. Oeningensis has, like the 

 other described fossils of the kind, veins on a much smaller scale than 

 has our new Nigerian form. 



The only described fossil of which I am cognisant which bears 

 a real resemblance to the Nigerian ones is that figured bj' Saporta in 

 1890,^ pi. ii, fig. 4. This, both as regards the size of the mesh and 

 the general appearance, comes very close to our fossil. Saporta's 

 fragment, however, is a small one, only 1x2 cm. in area, and gives 

 no indication of the potential size of the leaf. Saporta's plant is 

 described under the name TypJiacites rugosus, and he speaks of this 

 plant and another which he puts in the same genus as "fragments de 

 feuilles de Monocotylees, sans doute amies des eaux stagnantes, que 

 je figure en les rapportant, non sans quelque doute aux Typhacees". 

 The species were associated with the famous Nelumlium provinciale^ 



^ Marie C. Stopes, Catalogue of the Mesozoic Plants in the British Museum: 

 The Cretaceous Flora, pt. i, 1913, pp. 64, 167, 223, etc. 



^ Eudolf Ludwig, ' ' Fossils Pflanzen aus der altesten AbtheUung der 

 Eheinsch - Wetterauer Tertiar - Formation " : Palseontographica, vol. viii, 

 p. 80, 1859-61. 



^ G. de Saporta, Le Nehimbium provinciate des Lignites crctaces de Fuveait 

 en Provence, Mem. 5, Soc. Geol. France, 1890, pp. 1-10, pis. i-iij. 



