CONIOPXERIS. 107 



edition of the Geology of the Yorkshire Coast as Sphenopteris affinis 

 is probably specifically identical with that shown in our Fig. 6. 



The important point to decide is the specific identity of the 

 fronds with pinnules like those of Fig. 6 with more or less 

 rounded or sometimes truncate lobes and the rather longer 

 segments with acutely dentate lobes as represented in Figs. 4 and 5. 

 My belief is that these two forms cannot be specifically separated ; 

 both pinnrc have the same linear form, the pinnules agree in texture 

 and in venation, and one often finds that some of the pinnules 

 on such specimens as that of Fig. 6 exhibit a tendency towards 

 sharply pointed denticulations on the edges of the lobes like those 

 in Figs. 4 and 5. There are other reasons which lead to the 

 same conclusion, but these are stated in detail in the descriptions 

 of the specimens shown in Plates XX. and XXI. Cf. 52,597 

 (PI. XXI. Fig. 2). 



52,595. PI. XVII. Figs. 6, 7. 



These fragments illustrate the association of sterile pinnules like 

 those in 52,568 (PI. XVI. Figs. 4 and 5) with fertile segments 

 in which the lamina is considerably reduced and the tips of the 

 narrow lobes bear prominent sori. The fertile portion of a pinna 

 shown in Fig. 6 is no doubt specifically identical with Tympano- 

 phora racemosa of Lindley & Hutton, and with the fertile pinna 

 attributed by Leckcnby to Sphenopteris Murray ana ; the sterile 

 pointed segments are identical with those represented in PI. XVI. 

 Figs. 4 and 5, and these, as already pointed out, I regard as 

 indistinguishable from S. arguta, L. & H., and S. hymenophylloiJt*, 

 Brongn., as also from those of the specimens illustrated as 

 S. Murrayana in fig. 3, pi. cxxvi. of Brongniart's Histoire. 



Bunbury's species, S. nephrocarpa, the type of which is in the 

 Leckenby Collection, Cambridge, agrees with the fertile fragment 

 shown in PI. XVII. Fig. 6, and does not, I believe, represent 

 a distinct species. Cf. also Dicksonia clavipes, as figured by Heer f 

 from Siberia. 1 



Oolitic Shale, Haiburn Wyke. 



39,266. PI. XVII. Fig. 8. 



A fertile pinna agreeing with that of Fig. 6 and with. 



1 Heer (77), iv. (2), pi. ii. fig. 7. 



