THE JURASSIC FLORA OF SUTHERLAND. 



695 



is wrinkled and the segments show the venation clearly. The lower edge of the pinnae 

 is slightly decurrent as in the type-specimen. The specimen represented in figs. 86, 

 86A, though apparently characterised by a coarser venation, bears too close a resem- 

 blance to the other examples to be placed in a distinct species. Photo. 36, PI. IX.. 

 shows a fragment from the apical end of a frond, and a smaller distal fragment is seen 

 in fig. 79, PI. V. The obscure specimen represented in figs. 61, 61 A shows traces of 

 parallel veins in the almost filiform segments, and may be a smaller example of this type. 

 The specimen figured by Schenk from the German Wealden as Pterophyllum 

 Dunkerianum in his pi. xxxiv. fig. 5 * is probably identical with the British species 

 and distinct from the other examples which [ described in the second volume of my 



Text-Fig. 13. 

 A, B. Pterophyllum Nathorsli, Sew. (Gunn collection. 

 C. Nilssonia mediana (Leek.). (Arber collection, 539. 



A. From below. B. From above. 



Wealden Flora as Dioonites Dunherianus. In the true Dioonites Dunkerianus, as 

 represented by Schenk's other figures and by the English specimens, the segments are 

 longer and are attached to the upper face of the rachis. 



Like many other Jurassic species, Pterophyllum Nathorsti exhibits a great similarity 

 to some Rhaetic species, e.g. Pterophyllum sequale Brongn. figured by Zeiller t from 

 Tonkin, Schenk's Franconian specimens of P. Braunianum Goepp., and P. carnal- 

 lianum Groepp.J Among Jurassic species agreeing more or less closely with P. Nathorsti 

 are Ctenophyllnm angustifolium Font, from Oregon, § Pterophyllum distans Morr., and 

 P. Footeanum Feist, from India. || 



Nilssonia, Brongniart. 

 Nilssonia orientalis Heer. (PL IV. figs. 60, 63-65 ; PL IX. photos. 34, 40, 42 ; 



PL X. photo. 46.) 

 1878. Heer, Flor. Foss. Arct, Bd. v., ii., p. 18, pi. iv. figs. 5-9. 

 The specimens from the Culgower flora referred to this species differ considerably in 

 size, but agree in the possession of numerous unbranched lateral veins which are given 



* SCHENK (71). 



§ Ward (05), pi. xxii. 



t Zeiller (03), pi. xlx. . J Schenk (67), pis. xxxviii., xxxix. 



|| Oldham and Morris (63) ; Feistmantel (80). 



