1 64 SAGENOPTERIS. 



Museum Collection (pi. xviii. fig. 3), Bunbuiy draws attention to- 

 the occurrence of one "inversely heart-shaped" terminal leaflet 

 "cleft into two lobes." "This sort of variation," he adds, 

 "appears quite analogous to what we often see in the primordial 

 or seedling fronds of recent ferns." In the third edition of 

 Phillips' Geology of the Yorkshire Coast it is also suggested that 

 this cuneate form may be specifically identical with the longer- 

 leaved Sagenopteris Phillipsi. 1 Some leaflets from Australia figured 

 by Feistmantel 2 as Glossopteris spathulata-cordata bear a close 

 resemblance to Sagenopteris Phillipsi, var. cuneata. 



Although it is impossible to decide the question of identity 

 of Sagenopteris Phillipsi and S. cuneata, I am inclined to agree 

 with Bunbury that it is at least reasonable to suppose that both 

 forms of leaf were borne by the same species. Evidence of the 

 variation in the form of the leaf displayed by this genus is furnished 

 by numerous specimens (in the British and other Museums) of what 

 no one would hesitate to refer to S. Phillipsi : the size of the 

 leaflets varies considerably ; the proportion of breadth to length 

 and the distinctness or prominence of the midrib are characters 

 subject to considerable variation. Again, in the series of figures 

 of the Rhastic species Sagenopteris rhoifolia (Presl), and in the 

 drawings of species of this genus published by Zigno and Nathorst, 

 we have abundant proof of the variability displayed by the leaflets. 



There is a reference in the later edition of Phillips' work and 

 in the more recent notes on Jurassic plants by Nathorst to a larger 

 form of Sagenopteris leaflet, represented in the Leckenby Collection 

 and elsewhere, which agrees closely with S. Goeppertiana described 

 by Zigno from the Italian Oolites. A leaf figured by Feistmantel 3 

 as Sagenopteris, sp., may also be compared with this larger type of 

 S. Phillipsi. This form of leaflet is represented in Fig. 26, drawn 

 from a specimen in the Scarborough Museum ; a still larger 

 example of this form in the Manchester Museum has a length of 

 llcm. 4 



In spite of the striking difference between such a leaflet as that 

 shown in Text-fig. 26 and the leaflets represented in Figs. 2-4 of 



1 Phillips (75), p. 203. 



2 Feistmantel (90), pi. xx. fijjs. -5-8. 



3 Feistmantel (8 1 2 ), pi. xlii. A. 



4 Seward (00), pi. iii. fig. 8. 



