XXl] GLEICHENIACEAE 355 



(fig. 262, D) from Urgonian rocks of Greenland, affords a 

 striking example of a Mesozoic member of the Gleicheniaceae. 

 It is characterised by the dichotomous branching of the frond 

 and by the occurrence of arrested buds in the forks. The long 

 and slender pinnae, reaching a length of 9 cm. and a breadth of 

 6 — 8 mm., bear small crowded pinnules occasionally with circular 

 sori which are described by Heer as consisting of a small number 

 of sporangia (cf fig. 262, C). Several other Lower Cretaceous 

 species are recorded by Heer from Greenland, some of which 

 are probably unnecessarily separated from Oleichenites Zippei. 

 Examples of these are represented in fig. 262, A, B, C. 



A Gleicheniaceous species described by Debey and Ettings- 

 hausen from Lower Cretaceous rocks of Aix-la-Chapelle as 

 Didymosorus comptonifolius^ is very similar in habit to some 

 of Heer's Greenland species: this should probably be referred 

 to the genus Oleichenites. 



Oleichenites hantonensis, Wank. Fig. 263. 



From the Eocene beds of Bournemouth, Gardner and Ettings- 

 hausen^ have described under the name Oleichenia hantonensis 

 what is in all probability a true Oleichenia (fig. 263). This 

 species, originally recorded by Wanklyn^, is characterised by a 

 slender forked rachis showing what may be traces of arrested 

 buds between the arms of the branches, by circular sori of 

 six or eight sporangia and by the presence of peculiar tendril- 

 like appendages on the pinnae. If the description of the 

 tendrils is correct, this British species affords one of the few 

 instances of ferns adapted for climbing and may be compared 

 with the recent species Davallia aculeata (fig. 232, p. 299). 



Matonineae. 



The genera Laccopteris and Matonidium may be described 

 as examples of Mesozoic ferns exhibiting a very close agreement 

 with Matonia. 



1 Debey and Ettingshausen (59) PI. i. 



2 Gardner and Ettingshausen (82), pp. 43, 59, Pis. vi. i. 



3 Wanklyn (69). 



