212 PAGIOPHYLLTJM. 



branches referred to this genus suggests an araucarian habit, 

 and there is a decided probability that we may consider the fossil 

 forms as closely allied to the recent genus. As regards the 

 English specimens, in the absence of fossil cones we have no 

 very satisfactory evidence as to the relationship to modern forms. 

 Heer substituted Pagiophyllum for Pachyphyllum, on the ground 

 that the latter name had already been assigned to a genus of 

 orchids. The following concise definition is given in Zittel's 

 Handluch 1 : "Leaves spirally arranged, leathery, thick, triangular, 

 lanceolate ; spreading or closely imbricate ; decurrent at the base." 

 Solms-Laubach 2 justly considers Pagiophyllum a purely artificial 

 and provisional genus. 



Pagiophyllum crassifolium (Schenk). 



[PI. XVI. Figs. 1 and 2.] 



1871. Pachyphyllum crassifolium, Schenk, Palfflontographica, vol. xix. p. 240, 



pi. xl. fig. 8. 



1874. Pachyphyllum crassifolium, Schimper, Trait, pal. veg. vol. iii. p. 570. 

 1884. ? Pachyphyllum crassifolium, Saporta, Pal. Fran9- vol. iii. p. 600, 



pi. ccxxvi. fig. 1. 

 1884. Pagiophyllum crassifolium, Schenk in Zittel's Handbuch, p. 276. 



Type. Small and imperfect fragment of a branch. Gottingen 

 Museum. 



Schenk defines the species as follows : 



"Folia in ramulo spiraliter disposita, trigona crassa conica 

 falcata basi sessilia decurrentia." 



The specimens referred by Saporta to Schenk' s species were 

 obtained from some limestone rocks of Upper Jurassic age, in the 

 neighbourhood of Grenoble ; it is by no means certain that they 

 are specifically identical with the Wealden type. 



We may slightly extend Schenk' s diagnosis : 



Leaves spirally arranged ; sessile, with broad base, triangular, 

 somewhat falcate, keeled on the dorsal surface ; the leaf lamina 

 marked by fine parallel lines. Branching alternate. 



1 p. 275. 



2 Fossil Botany, p. 77. 



