Vol. 69.] OUR KNOWLEDGE OF WEALDEN FLORAS. 87 



Selaginellites^dawsoni, sp. nov. (Test-fig. 1, below.) 

 (Fairlight Clay, Ecclesbourne ; Bufford Coll.) 



The specimen on which this species is founded occurs on a piece 

 of ironstone, in close association with a sterile repeatedly-branched 

 shoot, identical with the impression represented in pi. i, fig. 8, of 

 the first part of the ' Wealden Flora', 1 and described as Planta incertce 

 sedis. The fertile shoot consists of a ribbon-like axis 3 cm. long 

 and approximately 2 mm. broad : at the edges of the axis are faint 

 broadly-triangular impressions of sporophylls, and the median 

 region bears numerous spherical sporangia. From the sporangia 

 both megaspores and microspores have 

 Fig. 1. — Selaginellites been obtained in an exceptionally good 

 dawsoni, sp. nov. state of preservation : the spores have a 

 (natural size). tuberculate outer wall. The microspores, 



which often occur in tetrads, are approx- 

 imately '04 mm., and the megaspores 

 •35 mm., in diameter. Both spores closely 

 resemble those of some recent species of 

 * Selaginella . In addition to the larger piece 

 of fertile axis there is another fragment, 

 the lower part of which is sterile and 

 identical with the vegetative shoot pre- 

 viously figured. 2 The discovery of the 

 spores, while confirming the former com- 

 parison of the sterile specimen with a lycopodiaceous plant, 

 demonstrates a closer affinity to Selaginella than to Lycopodium. 



It is proposed to publish an illustrated account of this species, 

 which I have named after Mr. Charles Dawson, whose labours 

 have materially added to our knowledge of the "Wealden flora, in a 

 forthcoming number of the ' New Phytologist.' 



FILICALES. 



? Htdropteride^;. 



Sagenopteris mantelli (Dunk.). (PI. XI, figs. 3 & 5.) 



(Ashdown Sands, near Fairlight ; Dawson Coll.) 



1846. W. Dunker, ' Monographie der Norddeutschen Wealdeiibildung ' p. 10 

 & pi. ix, figs. 4-5. 



The British specimens of this species previously figured are 

 rather smaller than those in the Dawson Collection. Fig. 5 shows 

 portions of two relatively broad leaflets, with clearly-preserved 

 anastomosing veins and a fairly definite midrib in the proximal 

 part of the lamina, attached to a common petiole. Some of the 

 leaflets figured by Dunker are identical in form with the Fairlight 

 specimens, and similar examples occur in the Bufford Collection 



1 Seward (94) p. 20. 2 Seward (94) pi. i, fig. S. 



