34 



THINNFELDIA. 



between the Lyme Eegis leaves and those described by Schenk and 

 Ettingshausen from Central Europe. The specimens from Australia 

 referred by Tenison-Woods ' to TUnnfddia falcala and Gleiclienia 

 lineata probably represent forms closely allied to T. rhomboidalis. 



52,751ff. PL IV. Fig 1. 



A fairly complete frond, 12-5 cm. long; the stout rachis bears 

 crowded, broadly linear segments, showing traces of a midrib in the 

 lower part of the lamina and oblique secondary veins. The edges 

 of the pinnules show a dark border which suggests a folding over 

 of the lamina, but a microscopical examination of the leaf-substance 

 affords no evidence of a revolute edge. The broad rounded tip 

 of the frond is well preserved ; the entire lamina at the apex 

 passes gradually through a lateral lamina with confluent lobes into 

 distinct linear segments. 



Lyme'Eegis. Purchased, 1874. 



Fig. 2. — ThinnfeUia rhomboidalis, Etl. No. V. 40,674. x IJ. 



52,672. PI. IV. Figs. 2, 2a. 



The apical portion of a frond of which the pinnules (Fig. 2«) 

 show very well preserved, dichotomously branched, secondary veins, 

 passing obliquely into a midrib. The dark border of the segments 

 is clearly marked, and the surface of the lamina shows numerous 

 small papillae. 



Lyme Eegis. Purchased, 1870. 



' Tenisou-Woods (83). 



