86 
A. C. Seward. 
Selaginellites Dawsoni sp. nov. Plate IV. 1894. Planta 
incertae sedis, Seward, Wealden Flora, Pt. I, p. 20, PI. I, figs. 8, 9. 
The specimens on which this species is founded were obtained 
by the late Mr. Rufford of Hastings from the Fairlight Clay, at the 
base of the Wealden series at Ecclesbourne on the Sussex coast. 
I have called this Wealden species Selaginellites Dawsoni after 
Mr. Charles Dawson of Lewes, to whose enthusiasm and generosity 
the British Museum is indebted for many specimens of plants from 
the Sussex coast. 
In the first volume of the Catalogue of Wealden plants in the 
British Museum a small branched shoot, agreeing closely with that 
shown in Fig. 1, was described under the non-committal title “ Planta 
incertas sedis” but, at the suggestion of Mr. Carruthers, it was 
compared with the slender spore-bearing branches of species of 
Lycopodium included in the L. Phlegmaria section. 1 Attention was 
also called to its resemblance to Conifer shoots of the type frequently 
referred, without any satisfactory evidence, to such genera as 
Widdringtonites or Glyptostrobus. 
While recently engaged in the description of Wealden plants 2 
acquired by the British Museum since the publication of the second 
volume of the Wealden Catalogue, I found the specimens represented 
in Figs. 1 and 2, both preserved on one piece of ironstone from 
Bcclesbourne but not actually in contact. The smaller fossil shown 
in Fig. 2 consists of portions of two axes approximately 2 mm. 
broad, with indistinct impressions at the edges of small crowded 
leaves and bearing several spherical sporangia 0.3 mm. in diameter 
on the surface (Fig. 2a). On treatment with nitric acid and 
potassium chlorate, a method recently described by Mr. Thomas in 
this Journal, 3 the sporangial walls were dissolved without revealing 
any microscopical features but numerous microspores and a few 
megaspores were obtained (Figs. 3 to 7). The microspores tended 
to adhere together in masses (Fig. 5) and not infrequently in compact 
tetrads (Fig. 3), the fourth spore in each tetrad being clearly 
distinguished on focussing. The microspores are approximately 
0.04 mm. in diameter and are characterised by a finely tuberculate 
1 Seward (94), p. 20, PI. i, figs. 8, 9. (Rufford Coll., British Museum, 
No. V. 2328), The specimen reproduced on Plate IV, also from the Rufford 
Collection, is No. V. 3151. 
2 A short account of Selaginellites Daivsoni, without illustrations, is included 
in the account of these recently acquired Wealden plants communicated to the 
Geological Society of London. 
2 Thomas (’12). 
