XL] STENORACHIS 55 



and for a Liassic species from Belgium, S. Ponceleti. Nathorst 

 subsequently adopted Saporta's genus. I have elsewhere suggested 1 

 the application of Stenorachis to various species described by Heer 

 from Jurassic and Cretaceous beds as male flowers of Ginkgoaceae. 

 Although there is no proof as to the morphological nature of the 

 specimens included in this genus some of them, e.g. S. scanicus, 

 present the appearance of seed-bearing shoots though, as Nathorst 

 is careful to point out, the seed-like bodies may not be true seeds. 

 I am inclined to regard Heer's supposed male flowers 2 (fig. 657) as 

 possibly fertile shoots of some members of the Ginkgoales which 

 originally bore seeds, but this view is merely tentative. Stenorachis 

 is employed as a designation for specimens consisting of a central 

 axis, generally fairly stout, bearing lateral appendages, whether 

 axial or foliar cannot be definitely determined, either simple or 

 forked and in some cases with terminal seed-like bodies but usually 

 with a small distal swelling or a few spreading lobes as in S. 

 Schmidtianus (Heer) 3 . Some at least of the specimens included 

 in this genus probably belong to Ginkgoaceous plants, though 

 in regard to others, e.g. S. scanicus, it should be remembered that 

 Nathorst inclines towards a Cycadean affinity. The genus Beania 

 was founded on specimens similar in general habit to species of 

 Stenorachis but in Beania the appendages have a comparatively 

 large terminal shield bearing on its adaxial side two seeds. 



Stenorachis scanicus (Nathorst). 



The type-specimen, first described in 1875 as Zamiostrobus 

 scanicus* and afterwards transferred to Stenorachis, is represented 

 by a comparatively slender axis 10 cm. long bearing, at a wide 

 angle, several lateral appendages, spoken of by Nathorst as 

 sporophylls ; these are split into two divergent arms each of which 

 bears on the side away from the fork an oval, longitudinally 

 striated, body described as thick and woody (fig. 656). The 

 nature of these bodies is uncertain and Nathorst is inclined to 

 think they are not seeds; he suggests as an alternative interpre- 

 tation that they are laminar structures in which microsporangia 

 are embedded. The morphology of this Ehaetic and Liassic 



1 Seward(12) p. 23. 



2 Heer (77) ii. PI. xi. ; (78) ii. PI. vi. fig. 8; (82) ii. A. pp. 18, 21, Pis. vi., ix. 



3 Heer (82) ii. A. p. 21. * Nathorst (75). 



