228 DR. A. C. SEWARD: 
with mixed sori and the D. Lobbiana type, represented by pinne free to the 
base and with sori composed of larger simultaneously developed sporangia 
like those of Matonia and Gleichenia, which forms the most striking depar- 
ture from the otherwise very uniform family characters. 
MATONINEÆ. AMatonia is represented by three species—if in opposition 
to Copeland, whom Christensen follows, we retain the Bornean fern Matonia 
sarmentosa, Bak. in the genus instead of adopting Copeland’s generic name 
Phanerosaurus. Matonia pectinata has a scale-covered rhizome bearing tall 
petioles splitting into fan-shaped fronds with comb-like pinnæ spreading 
radially through more than half a circle; the linear segments are slightly 
oblique and acute. Its fronds present a striking resemblance in habit to 
those of some species of Gleichenia, notably @. flabellata, @. quadripartita, 
and G. Cunninghamii Matonia pectinata occurs in Borneo and the Malay 
Peninsula. Matonia Foxworthyi from Borneo has fronds identical in habit, 
but with obtuse segments set square to the pinnæ. The sori, like those of 
Gleichenia, belong to the Simplices section. In Matonia sarmentosa, confined 
to one locality in Borneo, the rachis forks repeatedly and gives the frond an 
appearance very different from that of M. pectinata ; both branches of a fork 
may develop more or less equally, or one of them may develop fully while 
the other ends in an aborted bud. The polycyclic structure of the stele is a 
peculiar family character. 
Though not included in either the Matonineæ or the Dipteridinæ, the two 
genera Neocheiropteris and Cheiropleuria call for a brief reference because of 
their resemblance to Matonia and Dipteris in frond-habit and in certain other 
features. |. Veocheiropteris palmatopedata from Yunnan, regarded by Bower 
as a Dipteris derivative, appears to be identical with Matonia pectinata in 
the forked disposition of the spreading ribs, but, as in Dipteris, these are 
connected by a continuous lamina with a series of distal lobes. 
Cheiropleuria bicuspis, which is often associated with Dipteris conjugata, 
extends from the Malay Peninsula to the Luchu Islands, Formosa, and New 
Guinea. The reticulately veined lamina may be ovate and entire, bicuspid 
like the leaf of a Liriodendron or repeatedly and more deeply lobed. Bower 
describes it as a condensed and webbed example of the Matonia type.” 
While certain fossil Ferns are nearer to one or other of the two recent 
genera Dipteris and Matonia, at least in habit and venation of the frond, in 
others characters foreshadowing both living genera are combined. The first 
series to be considered includes genera which have often been definitely 
included in the Dipteridinæ ; but while this course may be defended, it is 
preferable to follow Nathorst and refer some of the extinct types to a 
separate family, the Camptopteridinæ, which he suggested might rank 
as a subfamily of Dipteridintæ. Good as some of the material is, the diffi- 
culty of subjecting fossil sporangia and sori to such minute examination 
as 
is possible with fresh specimens and the unavoidable incompleteness of the 
