XXXIX] PLAGIOZAMITES 589 



me to regard the irregularly serrate edge of the pinnae as the 

 result of tearing of an originally entire lamina and to compare 

 the specimens with Otozamites Beani (L. and H.). An imperfect 

 ovoid pinna recalling S. Belli is figured by Newberry from the 

 Rhaetic of Honduras as Sphenozamites robustus 1 . A French 

 Upper Jurassic species figured by Saporta as Sphenozamites 

 latifolius bears a very close resemblance in the form of the leaflets 

 to the Wealden plant Sewardia latifolia 2 . Kurtz records the 

 occurrence of Sphenozamites, S. Geinitzianus, from Rhaetic strata 

 in Argentina 3 , but I have not seen any figures of this species. 



PLAGIOZAMITES. Zeiller. 



The name Plagiozamites was proposed by Zeiller 4 for some 

 pinnate fronds and detached leaflets from the Stephanian of 

 Commentry and the Lower Permian of the Vosges. The better 

 preservation of the Vosges material enabled him to recognise 

 certain features which led to the substitution of Plagiozamites 

 for Zamites, the name originally employed by Renault for the 

 Commentry specimens. Plagiozamites bears a superficial resem- 

 blance to Zamites and Otozamites and differs but little from 

 Sphenozamites and Noeggerathia; it stands for pinnate fronds 

 bearing ovate pinnae with a sub-amplexicaul oblique attachment 

 to the rachis as is clearly shown in the species P. Planchardi (Ren.) 5 . 

 In the case of Palaeozoic fronds assigned to the Cycadophyta 

 on the ground of the resemblance of their pinnae to those of 

 undoubted Cycadean species, it is particularly important to 

 recognise the fact that decisive evidence as to systematic position 

 is lacking. We know nothing of the stem, the reproductive 

 organs, or the epidermal and stomatal characters of Plagiozamites, 

 and it is by no means certain that the genus is a true representative 

 of the group in which it is provisionally included. 



Plagiozamites Planchardi (Renault). 



Fronds pinnate ; pinnae ovate-lanceolate reaching 5 cm. in 

 length and 1-6 cm. in breadth, inserted obliquely on the rachis, 



1 Newberry (88) PI. vm. fig. 14. 



2 See vol. iv. 3 Bodenbender (02) p. 40 of the reprint. 



4 Zeiller (94) B. p. 174, Pis. vm., ix. 



5 Renault and Zeiller (88) A. p. 614, PI. LXVII. fig. 8. 



