56 



GINKGOALES 



[CH. 



species referred by Nathorst to the Cycadophyta 1 is, therefore, 

 uncertain. It is by no means certain that it has not an equal 

 claim to inclusion in the Ginkgoales ; there are no substantial 



FIG. 656. Stenorachis scanicus. (After Nathorst; A, nat. size; B, x2.) 



grounds for such relationship, but the resemblance of this and 

 other species of Stenorachis to abnormal seed-bearing shoots of 

 Ginkgo biloba rnay be significant (cf. fig. 631, D, p. 5). 



A similar but rather smaller type was described by Heer 2 

 from Upper Jurassic rocks in Spitzbergen as Carpolithes striolatus. 

 Nathorst 3 examined Heer's figured specimens and recognised one 

 of them as an example of Stenorachis, agreeing in the possession 

 of forked appendages with 8. scanicus and bearing seed-like bodies. 



The fossils described by Shirley 4 from Rhaetic(?) beds in 

 Queensland as Beania geminala are similar in habit to Stenorachis 

 scanicus and differ from Beania gracilis Carr. in the absence of 

 distally expanded sporophylls. 



Another Rhaetic species is described by Nathorst 5 as Stenorachis 

 Solmsi in which the 'sporophylls' have a different form and are 

 characterised by a distal, erect, laminar expansion deeply divided 

 into two segments : no seeds or microsporangia have been found. 



Stenorachis lepida (Heer). 



The species for which this name has been suggested was originally 

 regarded by Heer as the male flower of the Jurassic species Ginkgo 





1 Nathorst (02) p. 16. 



2 Heer (77) i. p. 47, PL ix. fig. 17. 

 4 Shirley (98) p. 16, PL xx. 



3 Nathorst (97) p. 20, PL i. fig. 15. 



5 Nathorst (02) p. 17, PL i. figs. 1821. 



