TiENIOPIEEIS. 125 



If we loot over a number of specimens of the recent genus 

 Oleandra, e.g. 0. neriiformu, Cav., we find that such characters 

 as the horizontal or inclined position of the lateral veins and 

 the degree of closeness with which these veins are arranged, 

 are by no means constant in the same species, or even in the 

 same leaf. 



In all such examples of the recent genus as I have seen the 

 apex of the leaf is acuminate, but occasionally in young leaves 

 there appears to be a similar termination to that in T. Beyriehii, 

 Sohenk. In some forms of Oleandra the leaf apex becomes 

 suddenly and sharply acuminate; if the tip of such a leaf were 

 broken off or bent back we should have an appearance very similar 

 to that represented in PL IX. Fig. 3 of the present Catalogue. 



The following classification of the Wealden fragments must be 

 regarded as provisional, and not one which rests on a very sure 

 foundation. 



1. — Tseniopteris Beyriehii (Schenk). 



1871. Oleandridium Beyriehii, Schenk, Palaeontographica, vol. xix. p. 221, 



pi. xxix. figs. 6 and 7. 

 1874. Oleandridium Beyriehii, Schimper, Trait, pal. veg. vol. iii. p. 514. 

 1882. Oleandridium {Tceniopteris) Beyriehii, Peyton, Quart. Journ. Geol. 



Soc. Tol. ixxix. 1883, Proc. p. 3. 



Ti/pe. Well-preserved leaf. In the Berlin Collection. 



Schenk gives the following definition of the species ' : — 



" Folia simplicia oblonga integra obtusa leviter emarginata basi 

 attenuata, 5-8 millim. lata, 6^ oentim. longa, nervi primarii 

 excurrentes, secundarii creberrimi tenuissimi angulo subrecto 

 egredientes diohotomi vel simplices." 



Frond simple, linear, entire, apex obtuse and slightly depressed, 

 gradually decreasing in breadth towards the basal end; breadth 

 about 5 mm. and length about 10 cm. Distinct midrib with 

 numerous lateral veins almost at right angles, or somewhat oblique, 

 and suddenly curved inwards towards the frond axis on the upper 

 surface, simple or forked. 



PalseontograpMca, vol. xix. p. 221. 



