14 Bower.—Studies in the Phytogeny of the Filicales. VII. 
Gwynne-Vaughan’s material was wrongly identified. There is difficulty also 
with material identified as Davallia repens , of which the anatomy has been 
described by Trecul, Tansley, and Gwynne-Vaughan as corresponding 
to that of Lindsay a. But I have material sent from the Calcutta Botanic 
Garden as Lindsay a repens which is identified by comparison with herbarium 
material as Davallia ( Odontoloma ) repens , Desv., in which the vascular 
structure is exactly that described by Gwynne-Vaughan for his L. cidtrata. 
In both cases I think that the Odontoloma identification is probably correct. 
The general conclusion will then be that the primitive Lindsay a-type holds 
for the genus Lindsay a, and that Odontoloma has solenostelic structure 
with a divided leaf-trace. 
There is, however, a converse anatomical point in this connexion. 
I collected in Jamaica a Fern named Davallia clavata which is ranked 
in Christensen’s Index as Odontosoria clavata (L.), J. Sm. It was, however, 
described as Lindsay a by Mettenius. 1 It has a typical Lindsay a- stele, and 
on this account I should uphold its reference by Mettenius as L. clavata. 
The fact is that Lindsay a, Odontoloma , and Odontosoria are very closely 
related. They include steps of anatomical progression from protostely to 
solenostely, such as maybe illustrated by L. linearis , Odontosoria acideata , 
and O. retusa. Any generic line drawn is necessarily artificial. 
Finally, the anatomical evidence confirms the exclusion of the so-called 
Lindsay a languinosa^ now recognized as Nephrolepis acutifolia (Desv.), 
Christ. For the axis shows two large meristeles, with multiple leaf-traces 
coming off from foliar gaps right and left, after the fashion of Davallia. 
It may be noted that dichotomy of the axis has been observed in 
numerous species of Lindsay a and Odo?itosoria. 
The general conclusion from these facts is that Lindsay a is a genus 
anatomically primitive, but very closely related to others which are more 
advanced, a conclusion to which the presence of dermal scales gives support. 
But in comparison with the Schizaeoid and Dicksonioid Ferns on the 
one hand, and the Pterideae on the other, the sorus o(Lindsaya has a special 
interest. It has been found in L. linearis to be actually marginal in 
its origin. As in Dicksonia the marginal cell by segmentation, as seen 
in any transverse section, becomes the apex of the receptacle (Fig. 13, 
i-iii). Two indusial flaps originate intramarginally, as in Dicksonia , 
differing in bulk, the ‘inner’ (abaxial) being the thinner, while the recep¬ 
tacle itself is slightly deflected to the lower surface. The first sporangia 
appear upon the extreme margin, and are followed by others showing 
a slight gradate sequence, especially on the lower side of the receptacle. But 
this is not strictly maintained, and at an early stage younger sporangia may 
be interpolated between the older, leading to a mixed condition (Fig. 13,1*1*1) 
which is quite marked in later stages and involves numerous sporangia. 
1 Fil. Nov. Cal., Ann. Sci. Nat., iv. 15, 1861. 
