XLViu] PITYOPHYLLTJM ; PITYOSTBOBUS 381 



PineSj and the presence of a fine transverse wrinkling on the lamina 

 is a characteristic feature. Pityophyllum, if employed for both the 

 narrower and broader forms, includes specimens which in all pro- 

 bability belong to Conifers of more than one family: some are 

 certainly Abietineous but the flatter and broader forms bear a 

 closer resemblance to leaves of some species of Podocarpus, Cefha- 

 lotaxus or Torreya. Nathorst, who instituted the generic name 

 Pityophyllum, recognises that many of the specimens so named 

 have no real botanical value. Detached leaves of the type included 

 in this comprehensive genus are of little interest; but it is note- 

 worthy that such species as P. Nordenskioldi (Heer) and similar 

 forms are characteristic fossils in Jurassic and Cretaceous strata. 



Pityophyllum Lindstromi Nathorst. 



Under this name Nathorst^ includes leaves described by Heer 

 from Cretaceous strata in Greenland as Pinus Quenstedti and 

 P. Peterseni, also specimens from Upper Jurassic beds in Spitz- 

 bergen. The leaves reach a length of at least 8 cm. and are 1 — 2 mm. 

 broad; the lamina tapers gradually towards the base and is more 

 abruptly narrowed in the apical region ; there is a prominent mid- 

 rib on one side and sometimes indications of two finer marginal 

 'veins,' also other longitudinal striations which may mark the 

 position of rows of stomata. These leaves are broader than those 

 of Pityites Solmsi and narrower than very similar specimens 

 described by Heer, Nathorst, and other authors as Pinus or 

 Pityophyllum Staratschini^ from Cretaceous and Jurassic rocks. 

 Pityophyllum, Nordenshioldi^ (Heer) from rocks of the same age is 

 another similar form having a tendency to a slightly sickle-shaped 

 and transversely wrinkled lamina (c/. fig. 776). Pityophyllum is 

 abundantly represented in Jurassic Floras*: the specimens are, 

 however, of very little interest to the botanist as it is impossible 

 to assign them to a family position in the Coniferales. 



PITYOSTROBUS. Nathorst. 



This name is used in preference to Feistmantel's genus Pino- 

 strobus, recently resuscitated by Dr Marie Stopes, on the ground 

 ■ 1 Nathorst (97) pp. 40, 67, Pis. v., vn.; (99) p. 20. 



2 Ibid. (97) pp. 41, 68, Pis. v., vi. ' Heer (78) ii. PI. ii. ; Nathorst (97) p. 18. 



' For references see Moller (03) p. 39; Seward (11) p. 53; Krystofovi6 (10) 

 PI. m. fig. 10; Thomas (11) p. 78. 



