49 8 Bower.—Studies in the Phytogeny of the Filicales. 
their mutual relations at the base of the lamina shows that they are 
on a plan essentially similar to that in Matonia (compare Seward, 1. c., 
pp. 175-6, and Fig. 1). It may then be concluded that the leaf in Cheiro- 
pleuria is a condensed and webbed example of the Matonioid type. When 
it is further remembered how the stages of progressive webbing are illus¬ 
trated in the genus Dipteris , as well as in the related fossils Clathropteris 
and Hausmannia , it becomes clear that this is the true interpretation 
of the peculiar and variable forms of lamina seen in Cheiropleuria . (Com- 
Text-fig. i. Trace of the vascular system at the base of the lamina ot a large sterile leaf of 
Cheiropleuria, showing the pedate relation of the main veins, after the manner of Matonia. The 
smaller veins show the * Venatio Anaxeti ’. x 4. 
pare Seward, Phil. Trans. 194, PI. 48, also Land Flora, p. 618. Also 
Seward, Fossil Plants, ii, pp. 386-94.) 
Between the main veins there is a reticulum, which is of the type 
described as ‘Venatio Anaxeti’ (Luerssen, Rab. Krypt.-FL, iii, pp. 17-18, 
Fig. 2,2,). This is the type also for Dipteris conjugata and Lobbiana 
(Text-figs. 2, 2 bis), and the same type, though in a more compact form, 
is seen in Plcttycerium (Text-figs. 13, 14). 
The venation of the leaves of young plants of the Ferns above named 
would appear to present a promising line for further comparison. For¬ 
tunately, among the material of Dipteris conjugata collected by Professor 
Lang on the Malay Peninsula, some plants have been found which were 
