1 6 Arber, Fossil Plants from the Ardwick Series. 



British rocks. One point of distinction between these 

 two species is the presence of characteristic marks on the 

 frond of the latter, which are regarded as derived from 

 bristle-hke hairs which grew on the surface of the frond. 

 These are rarely absent except where the preservation is 

 very imperfect. In the specimen figured on Plate i., 

 Fig. 3, the scratch-like markings on the frond are plainly 

 seen. Mr. Kidston^ has published the results of a critical 

 examination of this species in his memoir on the Somerset 

 Coalfield. This species is perhaps the most common 

 fern-like plant in the Ardwick Series. 



Note on Cydopteris^ Odontopteris, Dictyopteris, 8z;C. 



Williamson and Einney record Cyclopteris sp. from 

 Ardwick; and Salter, Cyclopteris flabellata from the same 

 locality. I have not seen any of these specimens, but I 

 may point out that Cyclopteris is no longer usually 

 regarded as a true genus. It is now known that Cyclop- 

 teroid pinnules were borne on the rachis of several different 

 species of Neuropteris^. 



The genera Odontopteris and Linopteris (Dictyopteris) 

 recorded by Binney from Ardwick are somewhat doubtful 

 determinations. They are both rare in Britain, and it is 

 possible that they may have been recorded from specimens 

 of NeuYopteris by mistake. There is no trace of such 

 plants among the Binney collection. 



On the other hand, Neuropteris tenuifolia (Schl), and 

 N. flexiwsa (Brongt), recorded from Bradford by Salter, 

 are very possibly correct determinations. Here, again, I 

 have not seen any specimens of these species. 



Sphenopteris ( Corynepteris) coralloides (Gutb.), recorded 



^Kidston ('88), p. 356. 



"See Zeiller ('OO), Fig. 80, p. 106. 



