Anatomy of Solenostelic Ferns. 735 
belong to Bower’s division of Mixtae. The presence of paleae 
instead of hairs is given by Prantl as a secondary character- 
istic of this group, and it held good in all the examples 
examined by me. 
Of the genus Davallia there now remain to be discussed 
the sections Humata, Endavallia , Leucostegia and Loxoscaphe . 
All the species that were examined in these sections proved 
to be perfectly dictyostelic, with the single above-mentioned 
exception of Davallia ( Leucostegia :) Novae-Zelandiae. The 
vascular arrangement was dorsiventral in every case, except 
Davallia Emersoni and D. contigua which are radially sym- 
metric. These two species form the sub-section Prosaptia , 
which, according to J. Smith, should be removed from the 
Davallias altogether. Upon the whole the anatomy of the 
above sections would agree better with the Polypodi than 
with the rest of the genus Davallia. 
Only a few species of Pteris are known to be solenostelic. 
One of these, P. incisa , is isolated with its varieties as the 
section Histiopteris both by Smith and H. Christ. Another, 
P. scabenda , together with P. viscosa , the anatomy of which 
is as yet unknown, form, according to Christ, the separate 
section Paesia. Jamesonia is solenostelic, and so also are two 
species of Pellaea. All these belong to Prantl’s third tribe, 
the Pterideae, the most primitive genera of which he considers 
to be Lonchitis , Pteridium , and Paesia . It appears, therefore, 
that the agreement of the anatomy with his arrangement is not 
so complete in this as in the two previous tribes. 
In his fourth tribe, the Polypodieae, solenosteles are still 
more rare. It is true that the Polypodiums of the section 
Dipteris are solenostelic, but Seward and Dale 1 have shown 
that it must be removed from the Polypodiums altogether. 
They even go so far as to give it a family to itself, apart from 
the Polypodiaceae. The only other case of solenostely that 
I am aware of in this group is in Polypodium punctatum , and 
here the vascular system so very closely resembles that of 
Hypolepis that, since Hooker himself has remarked that this 
1 On the structure and affinities of Dipteris, 1 . c., p. 502. 
